Normal Overstay fines are 500 baht per day. Maximum of 20k Baht. If you get caught overstating, you can be arrested, deported and blacklisted. In other words, get an extension of stay before the 26th of September or, if you can't, go home.
Good Luck. I just got my NON O in country last month (because I never had a NON IMM visa before and was NOT on amnesty) and will be getting my 1 year extension of stay next month.
As Benjamin has said a few times, forget about the NON O....But normally (Not now). Yes you normally can get a NON Imm visa in country from a 60 day family extension. BUT you ALREADY had a NON Imm before and are on amnesty.....For a NON Imm in country, you need to transfer the 400k in from abroad. For the 1 year extension it doesn't matter where the money comes from, as long as the balance has been above 400k, in your account, in your name, for 60 days. Also the best solution is to ask immigration directly, as these are not normal times.
You don't need a NON Imm visa. You already had one before, when you entered the country. The ED visa is a NON Imm visa, after which you got an extension of stay and then went on to Amnesty. So you will then do a 60 day family visit extension of stay, and then a year extension.
It is possible to get a NON O in country, but NOT while on amnesty. You are basically just changing the reason for extending your stay in Thailand to marriage from education...
I believe that is correct. For an OA visa, insurance can be from a non Thai company in your home country, as long it covers Thailand for the required amounts. If someone then gets an extension of stay in country, at the end of the OA, the insurance must be a Thai company.
James has made it very clear. Have the money in your bank for 2 months before you apply for your extension, and then keep it there UNTIL the end of the 30 day consideration period. So keep it in your bank for 90 days total to make SURE you get the final extension stamp for the remaining 11 months.