Risk assessment seems to be what most here are describing as "Safe" or "Raw" draft prospect evaluation. Then weight risk w/skill for each position. QB trumps all so naturally teams needing QB help are willing to assume more risk. Next it's real close value wise between a pass rusher in this case DE/OLB, CB & LT.
Hard to argue this. I tried, but failed and deleted.
If that isn't confusing then each team has their own draft board based off scouting departments work sometimes covering one particular player/prospect 2/3 years. Then comes the coordinators with their position coaches who run a specific scheme. As a draft nick,
I like to project based off historical data & use comps to current players successful in the NFL comparing their draft stock ratings when they came out. I have a problem with this, because that's a lot of perspective based extrapolation. I will see a player differently than you, so it all becomes "an eye of the beerholder" case of mental masturbation. I prefer to use stats and film and base a rating on how they play football. Just MHO. 
Picking early but not too early in the first, the Texans really have no idea who will be available #11 when they go on the clock. I think there is a better chance that Prince Amukamara is off the board rather than Aldon Smith. So if Prince is there do the Texans automatically take him? What if another team is on the phone & wants to trade up, offering their 2nd round pick? You must assess the risk of losing one of your top rated prospects vs the next level of players with adding a player who could start @ another position of need.
If the Texans take Akumamara at #11, the FO has proven it has no idea what it's doing. It is a proven fact that he can't cover top NCAA receivers, so why would one expect him to be able to cover ANY NFL receiver? In the NFL, all the players are All-Americans. This is why BPA wins hands down in my opinion. You're spot on as far as noone having an idea of who will be left at #11. Only Narolina has a good idea of who will be left at #2.
Pause for effect.....
Texans are changing defensive scheme, new DC, too many needs to trade up or stand pat. Trade down is risky if there is a specific player they covet, but if I can give up my man crush (Cameron Jordan) then they can to, take the best offer (there will be teams wanting to trade up) & address as many defensive needs as possible to help transition back to the 3-4 in Wade Phillips new D.