if i build a bank of bitcoin that operating like a traditional fiat money bank when people can save the money and get interest for their saving and also people can get a loan from my bank but the fiat money is change for bitcoin, the question is would you guys trust me to save your bitcoin on my bitcoin bank that i want to build ?
Then what's the sole purpose of exchange sites? wallets, online and offline?
Not trying to be rude but no I wouldn't entrust mine to your "Bitcoin Bank". There's a lot of risks involved in this idea. Not to mention that the rates would probably not ideal, Bitcoin is volatile after all. And "loans"(?) how in the world are you going to make it work?
Blockchain exists for a reason.