they might not even understand the numbers or words 🤷🏻, not to mention grasping the exchange rate to translate it to Thai baht or USD. In my case, my bank is Korean and so the app and everything is in Korean language (and the money is in Korean won, of course). Some countries write one million like 1.000.000 while others write it 1,000,000. Some others, reportedly, separate the numbers every four, not every three (India, I heard). In Korea, China and Japan, in some cases they use "man" so 1 million become 100 man (100만), although that's mostly used in company statements not bank accounts, but see the point.
they might be jealous, not of the visa itself, but of other fellow foreigners being able to come here with "less efforts" than them. I mean, I wouldn't, but that's a possibility.
For workcation you'll need either documents of your own company or documents proving you work for any other individual or company. Just saying you work remotely but not for whom, won't work.
I have exited and re entered many times during the year. Of course I have the money 🤷🏻 untouched, but they have ever asked me anything. Remote worker, not soft power, if that matter.
For soft power or workcation? I think that using an sponsorship for a workcation would be odd, as you're supposed to be a remote worker. For soft power it might be understandable. Of course what I think doesn't matter, but what I'm saying is that the Embassy can see it this way.
The visa is a PDF file, BTW never ever believe ChatGPT for serious things as visas, taxes, laws... Whether you can apply in Spain or Portugal will depend on whether the Thai embassies there accept applications from tourists or only from national/residents. You need to directly enquire with them. Many Thai embassies in Europe won't accept application from tourists, meaning you don't have an official residence status in that country.
currently they hold Dutch passport, yes. It doesn't mean they're not half-Thai, as their father is a Thai. They can easily get their Thai passport also.