@Bennett *******
applying for a non O within Thailand does not need insurance nor police checks. They require 800k in a Thai bank account transferred from overseas, but it doesn’t have to be in the account for any period of time (Jomtiem office excepted).
The hardest part is getting a bank account, but it appears you have that covered. Go to your local immigration office and ask for the handout of what’s required for a in country non O. Some offices interpret the rules differently.