OK ... I can now answer my own questions for others in the future...
glen and tkimble are correct. When you report to a new team at the end of a season, the 75% has already been taken out and the cash you see will all carry over to your first season for recruiting.
I can also say that if you purchase a FSS subscription when reporting to the new team (after the Final Four and before Rollover), that subscription will carry over to the new season.
I also suspect (but am not certain) that if you are staying at your current team and if you buy FSS any time after recruit generation, it will carry over to the next season as long as you don't leave the team.