I suggest you start using bitcoin before giving an opinion about its speed and cost.

Bitcoin as a payment system, currently has the fastest transactions among all payment systems including the banking system. The transactions reach their destination immediately (1-2 seconds) and on average it takes 10 minutes for them to become finalized.
In comparison in the traditional systems like the banking system, it takes months for the transaction to be settled and become finalized and same with altcoins considering they need a lot more "confirmation" compared to bitcoin to be considered final and that usually takes hours.

As for transaction fees, in 99% of bitcoin's lifetime the fee has been very low. Currently a normal bitcoin transaction costs about $0.03 which is very cheap.

The correlation I was trying to make but, its true we can't say it's completely scalable given the fact that, you've got to pay some transaction fee of which have been on the rise due to the by pass of most projects from hosting there ICOs on the bitcoin blockchain to Ethereum's.

Speaking of instant transactions with less fees, do you doubt we won't come to that? Not to mention, you could have a fee as low as $1 using whatever exchange to transfer stable coins using Binance smartchain. When the congestion is evenly spread across for most projects, we would have a speedy transactions.

Expensive; yeah there's an issue of that. However, segwit, and Lightening offer somewhat solutions to the expense problem, and in the future we'll likely see additional steps taken to reduce the transaction fees. However, due to the nature of Bitcoin, fees will always be a part of the network, and I'd rather higher security, a decentralised system to a degree, and paying a fee than giving up those benefits. I mean, a lot of people are already getting fees associated with their cards, they just don't realise it. Especially, if you own a credit card.

You are contracting yourself. You said, This your question is even rhetorical question because you have already answered the question by saying that btc is decentralized, and if btc is decentralized how can we solve the scalable nature of bitcoin? I dont think this can be solve. BTC is not own my individual so it will be hard to solve it.

Maybe, I'm just missing your point, however; What's your problems with the current security of Bitcoin? I mean, it isn't inherently insecure, otherwise it wouldn't be worth anything. So, what specifically do you not like about it, or what security aspects do you want to improve?

Bitcoin is also almost infinitely scalable. Probably more so than our current mass preferred fiat system. So, there's that. Plus, it's already decentralised more than our fiat system, which already makes it the better option in almost all metrics. Cash isn't as secure as Bitcoin, and I'd argue that electronic money, i.e those that are stored on banking systems also aren't as secure.

So, I'm struggling to really see current problems, but would like to hear them.

What exactly are you referring too here. Bitcoin is more scalable in certain areas, but without knowing exactly what limitations you're talking about, I can't really accurately discuss the scalability issues. Are you talking about the storage issue that we might run into etc?

We've got scalability already in the stable coins if you would consider that. Although, bitcoin remains the coin most crypto enthusiast look up to but, there are phases to the currency and network. One can't rush the other. Its a highly scares commodity and to have its fit value, we don't need to rush it but, allow the laws of demand and supply play Its part in setting the ask and bid price. With a few bitcoins yet to be mined, the issue with scalability and volatility will still remain. My speculations puts me at a point of a scalable BTC when the last bitcoin is mined.

Since bitcoin core doesn't support mnemonics that you could write down, the only option is to digitally store the wallet file itself. However, you may want to create more than one backup so that in case you lost the USB stick or it was damaged you could still recover your funds.

The file itself is encrypted.

That should never happen considering that bitcoin core is the reference implementation of Bitcoin. But it is open source and many people are using it, so it would be trivial to write a simple script that decrypts and extracts the keys inside the wallet file to be used elsewhere.

That's an overkill in my opinion.

A different encoding would provide no security if the thief knows he is stealing a bitcoin wallet.
Only a strong encryption can provide security.

Apart from which wallet to choose, if you're going to keep it for 20 years, you should look into cold storage (if you haven't done it yet). A wallet on a computer connected to the internet is always at risk, and 20 years is a very long time for malware to develop. If it's online and has never been online, at least you can be sure it can't be hacked.

You don't need internet access to export private keys (assuming you're not using a webwallet). That means you can always export private keys if you keep a backup of the wallet software. It doesn't hurt to actually test this to convince yourself. And test your backups (start from scratch with a fresh offline system), to ensure you can restore your addresses from there (ideally before funding them).

bitcoin.org has a wizard that helps you chose your wallet:
https://bitcoin.org/en/choose-your-wallet

It seems like there is some confusion about the basic concepts... I'll try to give a very simplified explanation about what is happening between seed/mpk/pk/address/derivation path/... mind you, this explanation is simplified.

Most recent wallets are either custodial (meaning: don't use those) or non-custodial. A custodial wallet usually doesn't let you access your private key(s), you're not in controll of your funds, so i'd advice against using those.

A non custodial wallet is usually a HD wallet nowadays.
Usually, they generate a seed phrase you can write down on a piece of paper in order to restore your wallet afterwards.
The seed phrase goes trough an algorithm to create a master private key.
Following a derivation path, private keys get derived from this master private key.

Usually, a public key gets derived from the private key, this public key gets hashed and the hash is actually the address.

Over the years, we moved from "default" wallet type. In the very beginning, we used pay to public key wallets. Then we switched to pay to public key hash "legacy" wallets, then to pay to Pay-to-Witness-Public-Key-Hash segwit wallets, and in the future even pay to taproot.

The thing is: the last 3 types of wallet (legacy, segwit and taproot) can be derived from the same master public key. That's why the same seed phrase shows wallets whose addresses begin with 1 (legacy), bc1q (segwit) and maybe even bc1p (taproot)

You can't.

What you can be sure of is that there will be some wallet software you can import your seed phrase in to. Most wallets which generate seed phrases,* Exodus included, generate them following the BIP39 process, which is well known and well documented. You can take a BIP39 seed phrase from any wallet and import it in to any other BIP39 compatible wallet and recover the same wallet with the same private keys. Even if every piece of wallet software on the planet no longer existed, and for some reason you could not access an old version of any wallet software, then the process to turn the seed phrase in to private keys is still well document and it would be fairly easy for you to recreate your private keys if needed.

You can import a private key in to any wallet which supports importing individual private keys. Private keys can be used to generate different types of addresses though (most commonly legacy (P2PKH), nested segwit (P2SH-P2WPKH), and native segwit (P2WPKH)), so you'll need to make sure the wallet you are importing to will generate the right address for you.

The addresses which begin with "1" are legacy addresses. The addresses which begin with "bc1" are native segwit addresses. It is preferable to use the segwit addresses as they result in smaller transactions and therefore lower fees. In terms of saving your private keys, I wouldn't at all - I would just write down your seed phrase and be comfortable in the knowledge that the seed phrase can recover all those private keys in the future if you need it to.

---

*Electrum is the most significant outlier here, which uses it's own seed phrase and derivation method. But again, this is widely known and publicized, so even if Electrum no longer exists in 20 years, it would be easy to convert the seed phrase back in to your private keys.

Even if they are doing their best to develop the project, you should not invest in this project because its volume is too small. You cannot make a profit from this project because no one is interested in it, just ignore it and find other projects better, especially you should choose altcoins with large volumes.

The coin is not active again looking at coinmarketcap data, with that huge circulating supply it means the project got abandoned and the value is heavily down, just ignore and find other good project

I don't know much about signature chain project, in fact I'm just hearing the name for the first time, to say the truth 3k daily volume is extremely low, this means there is not enough demand for the token, I hope you follow the rules of crypto investment that says 'invest only what you can afford to lose'? Do make sure that the team are very active and open to the public too, goodluck

Just stay away because that s a crap coin
https://coinmarketcap.com/currencies/signature-chain/markets/

This coin exist since 2018 and there was no even a single good result from the development progress. If you are looking for an opinion regarding it and that's a shitty project but if you are one of the advertisers from the signature chain i guess you will never hear that.

It's a dead project already just basing on the price on CMC, and why it is no data available? I'm confused, if the project has existed since 2018 then why CMC hasn't pull any data as of 2020? Isn't it a sign that this project is already what we call a shitcoin or dead coin?

I can't even find their github repository, another good indication is to check it out and see how the devs are doing from behind. If there are no updates then that is another red flag, just saying.