Dynasty Rules Help

12 Team Half PPR. 3 Divisions.
1QB, 2RB, 2WR, TE, 2FLEX, 1DEF, 8Bench, 2IR
Yahoo Scoring with a few changes. -2 INT -2 Pick 6. Rush Attempts .1 (Im curious) 15 PTS for 0 PTS Allowed, 3 for a Safety. 5 for 200 yard REC or RUSH/game. 3 for 400 yard PASS game.

I want to do 8 team playoff but is that too much?
Also the supplemental draft is that the rookie draft? and what are taxi slots?