Savings are any money not earned in the current tax year.it could be the sale of a house I your home country. The funds can then be transferred to Thailand tax exempt. Earnings, excluding government/state pensions, brought into Thailand are not tax exempt. All earnings in another country and not brought into Thailand are tax exempt.
No, if you bring any money I to Thailand as a tourist is non taxable. Likewise, monies earned, (savings) prior to becoming a resident (180 days) is non taxable regardless of how you saved your money.
All money earned outside Thailand and not brought into Thailand is non taxable.
You will need to get your marriage certificate legalised in your home country, then translated. You will need to send both marriage certificate and translated copy to Thai Embassy in your home country for verification of translation. Then you can obtain a non immigrant 'O' visa based on marriage provided you meet all the other criteria. Good luck.