I would doubt it if you could open an account for someone else especially on a tourist visa. He would have to be here to do it even if you are using an agent. I just opened an account and they now do a facial scan when you open an account, this was Bangkok bank
I have never used them but as far as am aware they are owned by a very prominent and successful business owner in Pattaya if this is the case I would assume they would be a trustworthy company . Maybe you may get a better answer hopefully from someone that has used their service
I think on that I just showed bank balance to show enough funds for visit. To be honest I don't think what ever you put there will effect your application
I think the tourist visa is 60 days and you can extend for 30 days. If you leave you can come back in on 30 day visa exempt then extend again for 30 days