You are very strong at wide receiver and tight end. In fact, you are a bit too strong at tight end.
I expect Dallas Clark and Jimmy Graham to both have solid years, but I wouldn't want Graham as my flex play. You would be better off slotting a WR or RB in that flex. Dallas Clark should be able to fetch a decent RB in return in a package deal with Reggie Bush or Fred Jackson.
Now, make sure you don't sell yourself short and end up with a worse flex play than Graham. It won't be the death of your team if you can't get a deal done. Clark and Graham are tight ends, but they both are in line to get a solid amount of targets.
All in all your team is solid. The tight end flex critique is a very minor one. Your team should be competitive, good luck