What programming language is that? I'm learning JS and it doesn't look like that, probably doesn't look like a JS framework too. Is that a python? I'm just curious.
The screenshot on the left is Javascript; the one on the right is Python.
Yes, that's true; as there is no way to actually verify assets that users have deposited to an exchange.
The solution is obvious - put your coins in your own wallet. Then it is trivially easy to verify every single satoshi you own.