Declan Ryan Nox. You can make it a touristy stay if you want to, but you have freedom of choice on that. Otherwise you can spend the seven days in one room in Bangkok, unable to leave, sitting on the bed being fed through a hatch in the door, but again that's your choice. Some people might prefer that.
Martin Lefkowitz. I think you need the medical certificate for the STV too, but compared to the OA it's crap. The OA gives you 12 months when you enter. Your only contact with immigration is for the 90 report, which is simple enough and even simpler if you're in Bangkok
There's nothing to say you cannot have more than one account (all have to be in your name) but I strongly advise against it. Immigration are incredibly anal about bank accounts and anything which goes outside of the square they see as a reason to reject. Because of the fragility of this 800k method I would urge don't do it. An IO has wide-ranging powers, one of which is "make life difficult for farang"!