Division games are always hard to call unless you've got Peyton Manning blowing you away 2 times a year.
The Titans and Jags both have their playoff lives on the line. Doesn't make them more likely to win, but I think they'll be more focused than a team like the Chiefs, Cowboys or Eagles coming in and not giving the Texans much thought, then finding out that they maybe ought to start playing before they mess around and get beat by the Texans.
I don't think the Texans have a chance against the Titans if Henry goes off for 200+ for a 5th straight game. Tannehill may not be much but the Titans didn't have Tannehill earlier and only threw the ball 10 times with Willis and still beat the Texans in Houston.
Jacksonville is a much better football team, and Lawrence is a much better QB than when the Texans played them earlier. Yes, the Texans have had their number recently, but all streaks come to an end at some point. And of course, at NRG it will likely be a Jags home game with their dozen or so fans packing in and outnumbering the half dozen Texans fans in attendance.
The Colts game is the one I think the Texans have the best shot of winning. BUT, it is in Indy where the Texans don't do a whole lot of winning. They'll likely be without Taylor so that helps. How poetic though would it be to start the season with a tie against the Colts and end it with a tie against the Colts?