Especially if you are drafting this early!?!
Defense first - I drafted MIN early last season and then got BAL a little later, I thought I was gonna score BIG there. I was still getting beat by ARI D, DET D, heck BYE D beat MIN a few times!
K - Pick one up the day before your first game, be sure to check the total K after each game and by week 3-5 you can see trends forming, which teams are settling for FG's. I did this 2-3 years ago and noticed Neil Rackers was getting an incredible amount of tries and still nobody had grabbed him (and our league had 9 of 12 owners living in ARI). I guarantee by week 5 the top 5 K's, by FFL points, will not all be owned. This is less true for defenses but still moreso than any other position in the game.
There are not any rules that say you must draft all positions. This way an injury in a pre-season gamemight not hurt you as badly.
QB: BREES, Cutler
RB: TURNER, MCGAHEE, R. JENNINGS, Leshoure, D. Williams, Hillman, Hunter, Dwyer
WR: CRUZ, GARCON, Amendola, Edwards, D. Baldwin