I would keep Charles. He had a long time to recover from the injury since it happened early in the season. He may start off a little slow but I think he will be top 10 by the end of the year. Also you can get a better WR than a RB with your 9th pick. good luck!
This. Having 2 of the top 9 picks helps you out here, and all those stud WRs that will be available (VJ would also be in that list if you release him). Charles is fantastic when healthy, and hopefully he is able to recover and preform. You have many opportunities to selcet top tier WRs, but you would probably have to use your #2 overall pick on him anyways. Also I think that VJ's numbers will be a bit down this year compared to his typical production, since Josh Freeman is a step down from Philip Rivers. You could wind up with 2 great WRs from these picks, and have a great foundation.
Also I saw you mention Ryan Mathews, I just wanted to say that many are projecting him to be a top 5 RB this year with no Tolbert to steal TDs, as well as Rivers losing VJ and the passing attack weakening. I saw another post in this forum talking all about Mathews, and since I saw his name, I was reminded of it. I'd keep my eye on him, as he should have a huge year if he stays healthy. Not to turn this into a Ryan Mathews board, just sharing my 2 cents.
Also, I noticed that you aren't keeping a QB, and you are planning on keeping Forte. Unless I didn't have better options, I wouldn't keep Forte, with Chicago bringing in 2 new big (in size) WRs for Cutler, as well as Bush who is a more than capable backup. He showed what he could do when DMC went down, and I have a feeling that Forte won't reach his potential this year. The Bears would love to be able to keep him long-term, but if he has another fantastic year, he won't be cheap, and I just get the vibe from them that they are planning on keeping Forte on a leash with all the new offensive weapons brought in for Cutler and co.