If your aren't classed as a % owner of the business ,she will need minimum 4 thai staff on payroll and you must meet the qualifications to be hired as a foreigner. example degree if needed plus recieve minimum foreigner taxable income.
If you are a registered % owner of the business, must be at least 51% Thai owned on paper, you will get access to a work permit as part of it , but there will be restrictions on what you can actually do . Normally a management role only. No hands on stuff unless you are qualified to do so.
Spend an hour with a lawyer who specializes in this area and they can give you all the answers to suit your circumstances.
Go to the branch your thai wife uses with her your passport ,your marriage papers and her tabien bahn. Open a joint account with wife. (Doesn't mean you.need to actually use it though.) Then walk in next day with her and same paperwork, ask for a 2nd account in your name only. They'll have a tough time refusing you if you and wife already have accounts they approved.
There are plenty of foreign CHEFS working in Thailand . Cooks are an entirely different thing. Foreign workers have a different minimum wage set by thai law that determines wether a work permit will be issued or not. In most cases its higher than what you would pay a Thai chef. Eg usa chef 60k a month ,Aust/Uk chef 50k a month, Indian chef 35k a month. Qualifications are also mandatory.
. Not always. If a foreign business owner is married to a thai, it drops to 2 thais on the payroll. And the required collateral drops from 4 to 2 million baht.
. I'd be careful with that advice. New passports often have new passport numbers, rendering passport number void on extension application if you don't wait for new passport first.