If your interest in moving to your parent's home country is not brand new and therefore it's more than something you're just beginning to consider, jump on a plane "tomorrow" and start reading Russian lit and spending hours on Reddit there. This assumes you haven't spent a ton of time there in the past because if you haven't then you will find immediate meaning living there. And if you decide to do one of those other things, or you just feel like it wasn't the right move, you can immediately fly back! No risk. Don't wait. Please. Just book a ticket now.
Good points. I was mostly thinking that instead of sitting wherever they are surfing Reddit and reading Russian lit they could be doing that in the one item on their list of potential next life steps where there's almost zero risk of getting into a situation that is difficult to get out of (they said they have a long list, but of the ones mentioned that one is "easy" to start doing today and ending tomorrow without complications).
Re taxes in particular I would guess there's no risk of hopping on a plane today and figuring that out later. As much as everyone likes to think governments are sitting there waiting to shout "got ya" it seems unlikely that any single government starts putting you on a tax watch list as soon as your passport is scanned at the airport.
