Yes, the rookie compensation system is a good approach taken by the NFL. Before the change in policy, contract negotiations were a much longer process, which often resulted in rookies signing a contract for more pay than they may have proven themselves worthy of over their first few years of professional football. The new system establishes fair pay over a specific time period that both allows the rookie to be signed to a team quickly and gives the franchise an opportunity to evaluate that players place on the team.
Yes, the rookie compensation system is a good approach to take for budgeting the salaries of rookie NFL players because it prevents one team with a lot of resources from basically enticing all of the best rookie players onto one team. It creates more equity in the distribution of quality rookie players.
In basketball, players on a rookie contract are capped out and most picks receive a salary based on where they were picked. This is a great idea and should work well in the NFL as well, although probably after the kinks get ironed out. Joey Bosa is just one of those kinks, and the league will come together with the players' union to figure it out before the next collective bargaining agreement.
I believe that professional athletes get paid an insane amount of money, and I do not believe that rookies should be paid so much money. They have only just started playing and they have not yet proved themselves. I do not think they should be paid that much in the beginning.