Bitcoin - lower fees, you have your own bank, transactions is easier and faster, identity of the owner is anonymous, volatile value
Fiat - higher fees, you need some company to put your money on, transactions takes some time and requires some verification if you are owning a large amount, stable value
Yes and in fiat you cannot huge amount of money with you physically as there is always a chance of money getting stolen or getting robbed but with bitcoins you can carry any amount in your bitcoin wallet and no one would be aware about it.
Looks like you forgot to add that anyone with access to your private key is the actual owner of the coins, so cases of theft are not alien here nor something exclusive to fiat currencies. One more thing, lower fees is now, used to be with Bitcoin as these days we are daunted with increasing cost for carrying out transactions in the Bitcoin ecosystem and this a real cause for concern for most bitcoiners.
I think that is true, when other people have your private key, they can send or manage you bitclins inside that bitckin wallet. But
this will only happen if you are kind enough to give your private keys to other people. Never do that , keep that safe. About the fees, it is really a pain in the ass. But we all know that the developers are having a solution for that. We better wait on what will happen in the future.
I wouldn't really say "kind enough" but rather I'll use "stupid enough". If you don't even know one of the basic stuffs in bitcoin, you shouldn't expose yourself just yet. Private key is called "private" for a reason. It's because it's not meant to be shared to other people. Sharing your private key is like giving out all of your bitcoins from that address.
The developers might have already think about a solution for the ever-increasing bitcoin's transaction fee but as long as they haven't implemented it on bitcoin yet, we will continue to experience huge transaction fees. A perfect solution is nothing if you fail to implement it.