My feeling about the current state of the OL is this...Lynch, Shanahan, and the other front office talent evaluators, through their actions (or inaction) during the draft, demonstrated that they felt that the OGs they had (with the addition of Cooper) were better than any of the young OGs they could have drafted. It seems they also felt that Kilgore was not only a liability at C but that his shortcomings in pass protection also affected the guards, who probably felt they had to cover for him at times. With the addition of Richburg, they probably felt like they also made the OG positions stronger too. Of course, that remains to be seen but if one has confidence in the front office and coaching staff, then we should probably feel OK about what they have right now.
The same goes for the pass rush. The team clearly thought that the pass rush and overall defense would be better served through needed upgrades and depth in the secondary, more than drafting an edge rusher that they had questions about. I distinctly remember someone (Lynch perhaps or Saleh) stating that the Niners were "close" to a lot more sacks last year and if the secondary could have covered guys for a second or two longer, the pass rush would have looked a lot better.
Now, the team did address both the OL (3 new starters possibly) and the pass rush (through the additions of several draft choices and FAs in the secondary). We'll see if they are correct but they seem to be confident in their decisions. BTW, these are the same guys that found George Kittle, Trent Taylor, and Adrian Colbert (3 starters) late in the draft last year so they appear to be good at eyeing talent. Maybe we should keep the faith until it isn't warranted.
Cheers!