Jamie Watt Multi Entry Non B visas for business purposes are now issued on a case to case basis and under exceptional circumstances by Embassies around the world. You can try your luck, don't want to sound negative, but you are unlikely to succeed in securing a multiple valid for 12 months.
To secure a Non IB, you need a letter from Thailand's board of Investment, i.e. you need to have a BOI approved company operating already in Thailand.
The Smart Visa for Entrepreneurs comes also with financial requirements to deposit 600K in Thai banks, and intention to set up a local company, plus overpriced local insurance.
At best you can hope for a Multiple Entry Tourist visa valid for 6 months given your circumstances and the current Immigration climate.
No, as you enter the Immigration 2, in front of you are the Immigration Booths and on the left hand side there is a way to go to the re-entry permit office. There is a booth on the way where they do a 200 baht photo and application service that can be avoided if you bring the photo and application completed from home.
To add on the above, Robert Lagas, don't some offices insist for people to go abroad and start fresh with a non O, that they further extend for 12 months? Do they happily extend permissions of stay derived from a non B for retirement purposes?
As Robert said above. You can continue to stay in Thailand on your current permission of stay and you can use your visa until expiry (continue to do 90 day border runs).
The advice provided above is given on the understanding that you do know what's in your passport. I.e. a multiple entry visa valid for 12 months issued at a consulate outside of Thailand that gives you a maximum permission of stay of 90 days per entry.
Ok so other options are cooking classes and self defence classes. The latter one in Chiang Mai if you are not too good at self defence it will take a long time to learn.