Yes, however, I would rename it after you close down bitcoin core.  Then open bitcoin core again and try to import your keys.    This way, once you import your keys you can be sure you have everything.   Then it is safe to delete your wallet.dat.

Yes. Although it isn't readable without decoding, it only stores your private key. To spend your coin, you need your private key. Do verify if you have copied down your private key properly as you won't be able to spend your coins unless every single of your letters and numbers in the private key are correct.

After learning that the humble bundle accepts bitcoin in another thread, i wanted to know what other cool places I could spend my BTC at, if you have some cool places that accept BTC, please share!

Start mining from some Alt coins. Yes! Because, directly mining bitcoin is might be not profitable. So if you're interested in mining try to mine some alt coins. Reffer minergate.


~Rude Boy

i wouldn't call mining efficient by any means, with electricity and hardware costs, the profits from mining are marginal at best and is only viable as income with a huge farm. also avoid cloud mining, most are ponzi scams but there are a few legitimate ones out there: https://bitcointalk.org/index.php?topic=878387.0
this thread should help. If you really want to mine though, purchasing an antminer S5 wouldnt be a bad idea.

There are two dangers particular to mobile devices:

1. Losing your bitcoins when you lose, break, or wipe your phone: You must back up your wallet or wallet seed. If you do, then you can always restore your wallet on another phone.

2. Losing your bitcoins through theft of the phone. If your wallet is not encrypted, then somebody can steal your bitcoins by stealing your phone. The wallet must be encrypted and allow access only with a password. If you do that, then nobody can steal your bitcoins.

Do not use a wallet that does not protect against either of these dangers.

never used circle myself but I have heard a lot of positive feedback from other users. far as i know it's only for US customers which is a shame, maybe I'll get to try them out one day. like odolvlobo said, Electrum is one of the easiest wallets to use. if you download a wallet app for your phone just make sure you don't keep too much btc on there.

I have bought a lot of bitcoins from Circle. They are very convenient. The drawback is that you give them direct access to your bank account.

I cannot recommend Coinbase because they track you and they will ban you if they don't like what you are doing with your bitcoins.

As for a wallet, Bitcoin Core is not a great choice. Before using it, you have to download the block chain (which can take days). And every time you start it up, it has to validate its database and sync the block chain (which takes several minutes).

I recommend Airbitz on your phone because it is very easy to use and very secure, and Electrum on your computer.