I think there are a few misconceptions here. This is said to be one of the deepest WR crops in the history of the draft. If we dont nab an OL in the first round, which his our biggest need, then I would be shocked if we dont draft a WR to compliment CC.
As for QB's, Mel Kiper has gone on record saying that this is one of the WORST senior classes in recent memory. After Leftwich, there are no sure fire-first rounders here. If some of the underclassmen come out, then this class may improve.
As for pther positions, I wouldnt take a safety in the first round - there are tons of good safeties available in FA every year. They can even be had for bargain basement prices (look at Brock marion this year).
OLB should also NOT be a top priority, since they are not on the field almost 50% of the time in our current defensive scheme. Its simply not worth it. Even Lavar Arringtom would be marginalized in Bates Defensive setup.
I could see us drafting a top flight DT if one drops to us, since Bowens is approaching 30 years of age and is getting up there in years.
Ultimately, if Im Rick Spielman (oh how i wish..), I look for an offensive linemen (the best available at any of the positions), or look at one of the WR's.