I think you should be commended for laying out the perfect offseason plan, and I am going to add my two cents to each of your bullets
1.) This is my only disagreement with you, I would let him walk and sign Nick Harper for much less.
2.) Let Fletcher walk like you say and I would use the money we would have spent on Clements, to bring in Lance Briggs. We can figure out later who will play the middle (Spikes or Crowell), but Briggs is a serious impact player. Jauron drafted him (I believe) and don't be surprised for us to make a run at him.
3.) Steinbach would be the most desireable guard, but if he is out of price range than maybe Dielman from San Diego could be signed at a much more reasonable price.
4.) The Bills could fill this need with Ian Scott. I have heard good things, but he sure was non-existent in the Superbowl. I don't know much about his play, but I hear he may be just what we are looking for.
5.) I love the Jarrett pick, but if Gaines Adams drops to us at 12 he would be hard to pass up. If we wanted more draft picks we could trade down and get Bowe from LSU.
This would be the perfect offseason - I have no idea if this would be affordable.