While I agree the Texans defense still has more than enough talent to win their division going away, this could have a negative domino effect in earning a bye and once they get to the playoffs.
I think it was Gruden that pointed out that the Texans really play a 5-2 defense..with Cushing being the key part of that "2". Reed, Barwin and Mercilus are all DEs that occasionally drop back in coverage. LBs Bradie James is on the decline and Dobbins is limited and there is nothing behind them. Cushing was important for both cleaning up any runs that cleared the DL and for coverage between the hashes. This makes them paper-thin in the middle of the field...which is not comforting against the teams in the conference they are really competing against (Pats, Ravens, Steelers, Broncos, Chargers).
They have 5 big games in the next 2 months (Packers, Ravens, Bears, Lions, Pats) with the last 3 on the road. I expect them to struggle over this period with 3-4 losses not being out of the question. The key for the Texans is just to gut it out and survive without additional injuries. If they can stay relatively healthy compared to the other teams in the playoffs, they still have a good chance to go far.