Just go and try different branches. It may be easier being away from tourist areas. The main stumbling block is proving where you live. Some banks will accept a sponsor so try your wife's bank first plus other banks will open an account if you buy their expensive insurance. Current money laundering laws have made it much harder to open a bank account. Good luck
there is no specific requirement but your re-entry is at the discretion of the IO so best not to just turnaround, unless you are with a visa agent group.
8 years ago it was 15 days by land entry. You still see this on some websites just like you still see only 2 entries per calendar year. This all confuses ppl just like calling visa-exempt entry visa-on-arrival
Unfortunately you cannot get a certificate of residence until you have extended your non-O visa as immigration does not know where you live until then. It is a catch-22, you cannot extend without a bank account and you cannot open a bank account until you have extended your permission to stay. 😃
It is very difficult to open a bank account now due to money laundering rules. You need a permanent address and proof you live there. Just because you have a non O visa is not enough. Some banks will open an account if you sign up for their insurance and some will accept a sponsor. Your best bet is to find a visa agent and pay them to open an account for you or you could just keep trying different branches.