Depends what country you are from, what fiscal agreement it has with Thailand. It also depends on where the money comes from. If comes from Thailand, taxes in Thailand up to 30% depending your bracket. If from other country, find out what are the fiscal agreements.
Ok. You can be on a tourist visa for up to 90 days. Then visit a Thai immigration office to ask for your mariage Visa. You will then be granted a 90 day « temp » mariage visa before you get your 12 months. This 3
Months granted « temp » will give you the right to open a bank account. Also, some agents are helping out for your bank account 😉