No option to change the selected currency under account setting is fine as long as there is a way to change the currency in the game. I'm not sure if Yas.bet has this feature as I have not tried/played their game.
There is no such option as far as I know. Yas.bet doesn't allow players to change currency except during registration, so the only way to change currency afterwards is to go through the registration process again and create a new account, which I think is a bad way and Yas.bet should really do something about it.
I agree on the point above that USD and EUR us mostly used or on where most people do prefer to look at.
Exactly.
I understand that they may be a popular casino in Iran, but if they are targeting international players, the IRR shouldn't be preselected when setting up your account. I bet there are many new users who fail to change that setting and end up with an account in a currency they are not familiar with.