Unless she teaches, a US citizens salary must be a minimum of 50k baht a month. I don't know what your wife's skills are, but it'll likely be extremely difficult at her age to get a job. Also coming from the US would she even want to make such comparatively low wages?
As you can see, these estimates are all over the place. It really depends on your lifestyle and where you want to live in Thailand. I've had months where I got by with as little as 30,000 baht but have also spent several hundred thousand numerous times. One thing I know for sure is I've been able to save a LOT more money here than I would've back home with a better lifestyle.
You need to contact your embassy, you cannot travel with a damaged passport. And all you idiots putting down this young person, seriously chill the fuck out.
I believe there is actually a gift tax in thailand but I do not know what the exemption amount is and it appears to be mostly voluntary. I've seen much larger cash deposits and nothing ever happens.
It depends on your destination, sometimes you don't have a choice of airlines. However, all the cheap carriers are basically the same for the most part. Try using agoda to book your hotels and use grab/bolt for taxi.
From what I've observed in thailand if you don't have money and you have criminal charges filed against you, a lot of jail time is pretty much inevitable.
