Asking the right question is sometimes harder than understanding the answer...so here goes.

After refusal of Extension of stay based on marriage I am now on visa exempt.

If I go to Bangkok to apply to change to Non Imm O based on marriage will my wife have to accompany me ?

Do I also have to have 21 days minimum remaining on my visa exempt stamp?

I have all the paperwork , embassy letter( proof of income) and tax return totalling 40K plus per month.

Many thanks in advance.

Yes to both (as far as I know - they were making exceptions to the 21 day requirement earlier).

//Edit: If you call government hotline at 1111 and ask for immigration they should be able to tell you the current rules in Bangkok.