Dieter,
I hear you about it being like comparing apples to oranges when we look at talent vs injury-likelihood when it comes to Sam but I think another way of looking at it is: it's not apples to oranges as much as it's taking all variances into account. If we graded QB prospects on what they could bring to the team, Sam's injury grade would be much lower than others (though, others would have grades - it's not as if there aren't injury concerns with some FA QBs) - it's just one variance among many including: arm strength, smarts, leadership, price, knowledge of offensive sxs.
Now, let's expand that to grading the QB position as a whole. All three spots (QB1, backup, practice squad). I'd even go so far as to grade Sam Bradford at a lower price and a rookie QB* and a seasoned backup (maybe Hill) as the best option for the QB position as a whole.
We may disagree, of course. Regardless, I'm super happy if I'm wrong and the Rams take a ham sandwich in the 1st round and install him as the QB and we win 16 games. My pride would never supersede my desire to win and kick a@@.
*PS, this crop of QBs in the draft will most likely be a really crappy bunch. I'm not sure there's a win there for us but it's still worth a shot.