If you have a multi-entry visa, that will be valid for six months. You can leave and enter Thailand as many times as you like with that visa up until the validity ends and you will get a 60 stamp each time you enter the country. That means that if you enter right at the end of the validity you will get another 60 days from that date.

Single entry visa is just that, one entry of 60 days and then you need to either extend that, or go get another one.

If that immigration office accepts reports by mail then you should be ok. If they accept online reporting then that would be even easier. If they don't do either then you could either tell the baby that you've got an important appointment with the Thai government and that they need to be a bit more considerate about their birthday, or not do the report and just pay the fine for late reporting when you get back. You never know, seeing as you have a reasonable excuse, they might let you off the fine, especially if you bring the new arrival with you when you get back to Ubon ;)

I don't think that is the reason. People applying for visas for the UK have to do that in their country of residence as well. UK citizens can apply for visas for Thailand pretty much anywhere.

For the MFA stamps you don't need the US embassy to get involved. Just have them translated into Thai and then that translation is what is verified by the MFA and stamped as being accurate.

As far as I'm aware, the Amphur office won't issue you with a Thai marriage certificate (as you are already married) but those translated and MFA stamped documents can be used at Immigration for your extension based on being married to a Thai national.

The name change document is what the Amphur office DOES issue when a Thai national changes their name, so you should do that. It will show that your wife is the person who changed her name from what it is in their records to what it is now (assuming she has changed her surname).

I think you're done with the US authorities, for now. :)

Good point. It's never a good idea to piss your landlord off. I was just thinking that if you stand to get fined by immigration for something they haven't done, it puts you in a difficult spot.

As for what you would lose, I guess that's a calculation you would have to make.

Can you report them to immigration if they don't?

Might be worth trying to get the baby's birth certificate sorted out and registered with the Cambodian embassy, establishing her Cambodian citizenship, before she travels. If you want to tag your daughter on to your wife's visa status in Thailand at a later date it might be easier if you've already got proof of her relationship with her mother ready, and the same rules that applied to the mother will apply to your daughter.

Just thinking ahead ;)

Same for me, except that I had no residence certificate. My wife preempted everything by asking the branch manager before I arrived and she vouched for me using her Tabien Ban (blue house book). She also has an account there which helped.

The required amount needs to have been there for the required time. So if you already have ฿300,000 left from last time then you just need to top it up to the full amount which then needs to have been there for the required amount of time.

There's no different version of any of those that includes a re-entry permit. You buy those separately. You can buy them at immigration when you get your visa, or extension of stay. Or you can buy them at the airport on your way out of the country.