You guys need a pass rush badly. And cornerbacks, and safeties, and maybe more OL. QB is a pressing need as well but you gotta go BPA and not reach for a guy just because of position.
I don't think Gabbert would be a reach. Luck was actually highly rated out of high school, just not rated as a phenom. Gabbert was actually even more highly rated out of high school. Gabbert has a ton of talent, but he hasn't been developed by a guy like Harbaugh. I don't think the difference between Luck and Gabbert is simply Harbaugh, but I think the gap between them would be substantially less had Harbaugh coached Gabbert instead.
I think the 49ers' offensive line is actually in decent shape. They weren't great in 2010, but they were developing two rookies on the line and their best lineman, Joe Staley, wasn't fully healthy. The main concern is that Chilo Rachal hasn't progressed since his rookie year, so another guard wouldn't be a bad idea, but I don't think offensive line is a crying need like it was a year or two ago.
Cornerback is a huge need. I rate cornerback and quarterback as the two largest needs. However, I think the quarterback position is harder to fill and if you get a chance at a franchise guy, you should take it. I think Gabbert has that potential...if the 49ers feel that way, I think they should take him at #7. Positional importance and scarcity factors into who the best player available is.
I don't think the 49ers are a tremendously talented team that simply underachieved under Singletary. But I think they are more talented than their record. They dropped several games to good/very good teams over the past two seasons by close margins. While I think they can stand to improve in multiple places, I think the two places that could improve them a lot, in a hurry, are quarterback and cornerback. If they were to find strong performers at quarterback and one of the cornerback spots, I think they could reach a tipping point and win the division going away (the fact that the division sucks is certainly part of that). They need more than one strong off-season to be a serious contender, but this might be their best chance to get a franchise quarterback.
All of this relies on the fact that I don't believe Gabbart is a reach at 7. I think he's the best quarterback prospect in the draft, with Luck out, and legitimately a top-ten talent. If I didn't feel that way, I wouldn't advocate his selection. If the team views a defensive lineman or cornerback as clearly the best player when they select, I would be happy with that pick.