Offense I have very little problem with in terms of personnel. Playcalling by coaches is another thing entirely. Other than trying to get out of Miles contract, and replacing both the LG & RG is all we can really do that makes sense. That isn't really big on my priority list.
DL - Ware isn't going anywhere (just focus on getting all his ailments in check, and come ready to have a healthy season). Selvie deserves to come back, he played well. I'd take paying Hatcher over Spencer right now. Probably would be less overall salary in terms of years.
LB - Sean Lee is the only definite back. I'd like them to move him to OLB. He is a good pursuer, so it would make sense to have him cover flats, screens, and RBs trying to turn the corner. Great player, but we need to change some thing on the defense, and I'm not too convinced about having him defend the middle, regardless of the 4 picks. Also if he is going to miss games like he does, I'd rather have to replace an OLB which is a little less important than having to fill in the blanks with our MLB.
Really no one else should be safe on defense. But at the same time, we have no idea because of injuries. Maybe a new scheme works, but we can't afford to just assume well if we had a different defensive scheme we'll definitely be better and make no moves.