I heard that's what they do in Iran. You can get a 'wife' for the night and then divorce her in the morning, and the religious authorities are fine with this apparently 🤔
That's right. I hear for the COE application you can send in a copy of your visa application as proof that you've applied - you don't need to wait for the visa
Personally I went the TR visa route, but I probably could have saved money by going visa exempt and then extending... but I didn't want to have to change my flights around.
Many countries have the rule that you can only apply from somewhere you have residence (can be different to your passport country). But I'm pretty sure Thailand don't have this rule - although it could be down to the individual embassy to decide
The STV is not so good if your plans are in any way flexible, because you have to book the entire 3 months accommodation before applying for the visa. Also since they're discontinuing it in September, it could be that they refuse renewals after then too.