I'm not sure a team makes a big jump for a DE, even one as talented as Clowney.
If one or more teams want to move up for a QB, unless they absolutely have to have a certain one, the advantage would be to trade with us and pay less to get the 1.2 intead of the 1.1. Of course, the same reason cited that the QB group lacks star power (though I think some scouts are pretty high on Bridgewater, Manziel and even Bortles), would be a reason for other teams to not want to pay to move up to the 1.1, viewed from that perspective.
I agree that HOU (and I might add ATL, MIN and even WAS, though we benefited ;^) ) are unusual teams in the top 10 of the draft being just a year removed from the playoffs. I agree with PhxRam, HOU doesn't have lots of holes. I also agree if they don't like the QBs they shouldn't reach (also I'm not convinced Clowney is a great fit in the 3-4, and though I don't know if O'Brien intends to remain in that front/alignment, the hiring of Crennell as DC suggests so). But if they do like one or two, than they can't afford to move down. They really, really need a QB for the future (Schaub and Keenum aren't it, IMO - remember when the HOU fans cheered when Schaub was injured... there could be an insurrection if they don't make a decisive move at the position either through trade, free agency or the draft, and they are conveniently situated at 1.1). The HC reportedly likes smart QBs that are gym rats and film junkies, and Bridgewater fits that profile (but if you want a hard partying, drinking dude and orgy maven, Manziel is your boy!). If HOU is more like the 2012 iteration and 2013 was an aberration (they lost a half dozen or so games by a score or less, and were snakebit by injuries to Cushing and Foster, Schaub crashed and burned, etc.), they very likely won't be anywhere near this kind of Park Place and Boardwalk draft real estate in 2015. Now would be a good time to grab that potential franchise QB, if they think there is one.