Canada just straight up participates in less tournaments internationally at these levels, at least in the ones where Sweden also are. As far as I know they are not intentionally and consistently selecting worse players. The US have a NATIONAL DEVELOPMENT PROGRAM where they put resources into ONE TEAM that likely most professionals on the SHL teams have not even sniffed in their life. That team gets selected at like 15 years of age. So your argument is completely off here. We haven't even accounted for the fact that both those countries just have access to way more good players as well, for obvious reasons.
I don't think 57 players is a low number by any means, given how big the difference is in talent and ability between the better and worse players are at this point. Having spread spots out more would likely have done nothing for those extra players in question anyways, they are so far behind the pace anyways. Getting to play 3 games in a sweden jersey is not changing their trajectory, as opposed to efforts from the individual, and the clubs(where the biggest effect could actually, and where the problem actually is in swedish hockey compared to the north american ones). Even if I bought into the ludicrous assumption that a couple international games was a big boon for those players(keep in mind they would get SHREDDED unless the other countries did the exact same) is that worth taking away those few resources we have that were allocated to the top players? Swedens issue is not developing milquetoast, medicocre and boring players, we are the best in the world at that, per capita. Our problem is developing and getting the absolute most out of our most talented players.
The NIU goal is honestly completely ridicoulous. What makes us base it on the amount of NIU programs? Have you seen how terrible some of these programs, especially the lower end ones, are run? Not only are they terribly coached, even teams with big names that aren't neccesarily top teams, at least at j18, actively select worse players from their own, than give more talented players from other regions a chance. A LIU program like Strömsbro beat Mora 4/4 games and outplaced both them and Karlskoga this year. They likely make nationell straight up if they played in regional norr or öst instead. Just like Flemingsberg actually did(and outplaced teams like Björklöven and Timrå obviously). Yet those teams does not count, but NIU teams does for whatever reason.
I probably share some of your concerns, but I don't think your arguments and "solutions" are very grounded or well-informed.