Responses: 100% carryover - It has been said before that this would just make the rich richer. To go with this idea should be minimum recruiting efforts increase with ratings of the recruits. Example: Top 25 recruits would require an initial minimum 20 CV's for all teams. Top 10 in each position would require 10 CV's. Rest of top 250 would require 5 CV's.
OR
Go with complete auction system in two day rotation. Days 1 & 2: Bidding starts and winning bid gets player at end of day two. Winner pays the fee, everyone else gets their money back and round two (days 3 - 4) start. Again winner pays the fee and gets the recruit on day 4, everyone else gets their money back. Round three repeats on day 5 & 6. Round 4 on the last day has winners getting the recruits and losers getting their money back for the next season. Sims bid amounts that would keep the winners amounts honest, decreasing down each round.
Moving - just sounds like no fire contracts which we essentially have now.
Recruiting during season - +++
Transfer portal - Maybe for after the junior year for players who aren't playing. Should have a message "of concern" at the beginning of the season to alert the coach. Not for set number leaving.
Injuries - I agree BUT - with limited rosters keep total numbers low for any one team. Also I would like to see a fatigue component tied to durability. Low durability may mean a player may need to sit out a game during the season due to being tired.