I agree entirely. I think rich clubs hoarding lots of young talent (in many cases not because they think they're going to be good enough just that they don't want anyone else to benefit) is detrimental to the game overall and the international team.
For me, I'd bring in a maximum squad, say 40, of players on pro contracts. Doesn't matter what age, nationality etc - 40 max. That'd put a lot of these youngsters available for free at the end of their academy contracts, giving teams lower down the pyramid the chance to bring on better players and upping the overall standard as well as potentially levelling out the competition somewhat and making it more competitive. Other clubs have to put up with (and often pay a fee) for the errors as they learn and then the parent club gets a finished article for a relatively inexpensive initial outlay. Grossly unfair system.
In financial terms I think it'd lead to a huge disparity in wages because even more funds would become available to pay the top level players but I'm not overly bothered about truly top class individuals being highly paid. It's when you've got youngsters (essentially trainees), who've never played a first team game, on contracts 5x+ what first team regulars are on just a league or two further down. Imagine the office junior/intern on a wage many executives would be happy with!
Besides that it'd be good for the players development, getting into 'proper' games at men's level than U23/reserve level. So much potential is wasted in players sitting on pretty lucrative contracts until 24-25 when they end up being released and then struggle to cope when they have to face the realisation of what football is like for the vast majority of players because they've never experienced it.
Another thing that I'd consider is the U24 compensation rule being altered so that no compensation is due if said player hasn't played a first team/league game for their parent club in the previous season.
Shame JH isn't around for a second revolution!