2. You can never be added to the blue Tabian Ban that Thai are listed on. If you really wish you can get a yellow tabian ban for non Thais
3. The 800K only needs to be in a Thai account for two months and a day, so maybe a bit premature to put it in now.
I'm also 52 and have been extending my Non-O for eight years. Costs 1900 baht per year.
Best of luck, this is a great place to be!