re: Changing rules during the season?

As far as this year, you can't change the rules.

Next year, play in a 5x5 H2H league using ERA, WHIP, K/9, saves, and either wins or QS (whichever you prefer) for the pitching categories. 3 of the 4 applicable SP stats are ratio stats, therefore it won't swing the matchup towards whoever just starts the most SP. If someone is a good enough manager to where he can consistently start FA SP with success, tip your cap because he is a better fantasy player than you are.