I introduced kbin to someone today who asked what the fediverse was. I answered for them of course, but it made me realize that the concept is still technobabble for most people. The average joe probably doesn’t care or notice that server A is really talking to server B. Just have them find out on their own and if a mass migration does need to happen from A to B, just make a standard announcement.
Absolutely - I’m coming from the assumption that they are given a list of reasonable instances (for example from the kbin front page or from recommendations).
Among a curated list of servers, it’s probably best to join one without assigning too much importance to it, and rather change instance later should you be unhappy. But of course, some instances should not be considered, and some might prefer to join an instance with stricter/more lenient moderation right off the bat.