you can't use the 65k baht per month to apply for a Non-O visa inside Thailand. You can show the equivalent in your home country bank to apply for a Non-O visa inside your home country before you travel to Thailand, but you would still need to show 800k baht in a Thai bank to get your 1st 12 month extension inside Thailand. During that 12 period you could transfer 65k baht (which you can spend) each and every month for a full 12 months prior to applying for your 2nd extension and use that option then. As to problems filling out forms, they're not extensive so I'm sure you would manage, mostly you just need to be able to write your name, address and passport number along with a couple of dates
A tourist visa is a 60 day visa that can be extended by a further 30 days, a visa exempt entry is currently similar. Both can be converted to a 90 day Non-O visa at most immigration offices but you need a minimum of 800k in a Thai bank transferred from overseas and between 15 and 21 days left on your current stamp in order to apply. It is still possible to open a bank account on a tourist visa but it's not easy and can require visiting many branches of different banks until you find one that will accommodate you. It may be easier just to take a trip to a nearby country and apply for the 90 day Non-O visa there, once you have this it's much easier to open a bank account