If I decided to save bitcoins in bank, how will deposit rate be changed compared to dollar or other currencies? Will it have much lower percent?
I don't think if there are any Bitcoin bank now neither online nor real life so that you can find another way to save your Bitcoin. Maybe you should try "Cold Storage", it's really a way to store your Bitcoin for long time, if it's the way you are asking for.
There's no such thing of Bitcoin bank. If it there's a bank I won't hesistate to deposit my btc there. I'd rather put it to my offline wallet, its more safer and secured. Saving bitcoin in your wallet will have a grow of interest unlike fiat that devalues over time.