You can stay 60 days on a tourist visa. Depending on your nationality you may be able to extend that once for 30 days.
Again depending on nationality you may be able to exit Thailand and re enter with no visa for 60 days. If you can you can extend that once for 30 days too.
mentioned all embassies now require an online application via the evisa system.
If you apply for a Non immigrant visa from the US then you’ll find it way easier to open a bank account that will allow you to apply for the yearly extensions.
You can enter visa exempt or on a tourist visa (why pay $45 for one when you get the same amount of days for free). But you’ll have an incredibly hard time trying to open a bank account to satisfy the requirements for an extension. It may be possible to do so but quite possible that you can’t.
If you apply for the Non O in the UK you need to provide what they ask for. Funds don’t need to be in a Thai bank, just the equivalent in any bank in your name.
When you get to the extension stage within Thailand then funds will need to be in a Thai bank in your name only.
You can’t get the first year extension (UK based as your embassy won’t issue an income affidavit) other than using banked money. For the 2nd extension and further ones you can switch to the income based international transfers of 12 months of 65k per month method.
You’re not going to get an “accompanying” visa for a spouse in any consulate or embassy around this area. They stopped issuing those years ago. For a kid yes. I don’t know the specifics but their website should give details.
The only way these days to get a “piggyback” visa for a spouse is if the main visa holder applies for a Non OA visa in their home country - which requires a health check, police check and insurance. Then the embassy may issue a Non O to the spouse. Not all will.
Although theoretically possible to extend as some have already it’s almost certainly easier to bounce out and back for another 180 day stamp.
1,900 baht to extend will probably be cheaper than a bounce for many, but providing the copious amounts of paperwork and proof of study/earnings will make it seem the easier option in the long run.