The best part of the fediverse is that anyone can run their own server. The downside of this is that anyone can easily create hordes of fake accounts, as I will now demonstrate.
Fighting fake accounts is hard and most implementations do not currently have an effective way of filtering out fake accounts. I’m sure that the developers will step in if this becomes a bigger problem. Until then, remember that votes are just a number.
I like that idea. A twist on it would be to divide the votes on a post by the total vote count or user count for that instance, so each instance has the same proportional say as any other. e.g. if a server with 1000 people gives 1000 upvotes, those count the same as a server with 10 people giving 10 votes.