Wow, big post. Reminds me of me, so I have to answer it.
QB - I agree exactly with your thinking on Warner. Ok, so IF he starts, you won't know it until right before gametime of the Sunday night game, and if he's inactive, your choices are Matt Leinart or nothing, and you'd have to roster Leinart ahead of time to do it. And IF he starts, against a MIN pass rush that knows he's one solid hit away from being a spectator, then what? Hell, no one would admit doing it intentionally, but is it worth a well timed 15 yard roughing the passer flag to get him out of the game? Ummm....YES! I roll with Alex Smith and thank the FF gods that Singletary has seen the light with the spread offense.
RB - MJD and Addai are no-brainers, to me your choice is between Maroney and Grant. Raven run D not as good as it used to be, plus for Grant. Every down back, plus for Grant. Recent hot streak, plus for Maroney. Gets the ball in the red zone - BIG plus for Maroney. That's what tips the scales for me, Maroney is the guy. 8 TD's in his last 6 games.
WR - I don't have any issues with using two players from the Jags offense here, because it's a home game and a good matchup for them. MJD is going to get his basically no matter what. And for some reason David Garrard plays like an NFL QB at home, and a small time college QB on the road. I have MSW, and I'm still stabbing the Garrard voodoo doll with straight pins for that putrid second half against the Niners. I think Avant has a great opportunity here with DJax out, but Austin has been getting it done for longer, and I don't think the Giants can cover him. Austin is my pick here. Good luck!