Ethics individualist emigration

Uh, I can't say I've ever really thought about the third one, but in general I'm very suspicious of anything that sounds like that campist approach of dividing the world up into "good" and "bad" categories - I know a fair few people who've moved to the UK as economic migrants, and I don't think I'd judge them as implicitly supporting the horrors of British colonialism, the war in Iraq, Universal Credit and so on, and it would be ridiculous to say that Latin American migrants locked up in detention centers are somehow Trumpists, so I can't see much grounds for applying those standards elsewhere.
When it comes to wealthy woke performers, obviously they have a bit more agency, but I still think the best thing is not non-engagement with the "bad" countries, but to use their platform in such a way to make it clear that they don't endorse the regime - so, in case Radiohead or Taylor Swift, or their East Asian equivalents, are reading this, I wouldn't really have a problem with them playing Israel if they used their time in the country to promote, and hopefully raise money for, groups like Anarchists Against the Wall, and most importantly if they joined in with demonstrations like the Bilin Popular Struggle Committee ones, which could have quite a big effect, at least in terms of forcing the IDF to either treat said demo more gently or else causing an international scandal when they teargas Justin Bieber or whoever.
Similarly if like Lil Nas X or Lana Del Rey or whoever played Moscow next week and gave a speech from the stage about the Network case, that'd be great - admittedly, I don't think it's that likely, but that's the advice I'd give to any wealthy woke performers who are interested.

1. "...If you move to a country with an authoritarian, repressive regime as an ordinary economic migrant, are you offering implicit support for it?..."

If I moved to a relatively non-repressive country which then becomes authoritarian, do I move out?

2. There is always a reason not to perform. 2003 invasion of Iraq, the complicity today of Syria and Yemen. I would suggest it is for the performer to judge the effect of a boycott or not, what advantage can be made. Eartha Kitt ignored the ban to visit South Africa and successfully exposed apartheid practices more than if she didn't go. Anti-Zionist BDS is presently the main focus. Celtic FC played an Israeli team. The fans flew Palestinian flags at Parkhead but boycotted the away game.

3. Marriage has always been a way out of poverty, particularly to foreigners in Thailand and Philippines, not just the individual but the whole extended family usually benefits, as they do when someone migrates and send remittances home. Nearly it is always female marrying males but there are also many international gay relationships. I also recall being in Gambia where there were elderly white women with younger black men. I encountered similar in India. Obviously not as prevalent as Pattaya and the commercialized sex resort it is

Mail-order wives is an overly simplistic description similar to trophy wives.

Trying to make moralistic arguments within all the contradictions of commodifying capitalism is almost an impossible task.

I don't support any actually existing country in the world, including the former great Empire and warmonger that I was born a citizen of. I kind of think everyone should live where they want really.

taxes.

1. No, unless you participate support it. ie UK citizens moving to South Africa under Apartheid.
2. Yes, that is offering implicit support. You shouldn't shill for oppressive regimes, especially if you don't need the money. Unless the average person is doing something directly linked to the repression then this doesn't apply of course.
3. Anarchy doesn't really respect marriage and sex work is ok. So if you want to marry for financial reasons then I don't think it matters too much a slong as you aren't deceiving people.