Did you check your upper ball joints or steering btw?
Is the caliper sticking? I would drive it some and put your hand on that wheel after 4 miles or so ...compare to the other side. Could be your caliper sliders are rusted up pretty well and it heated up the new rotor (warped it). If you feel that wheel after, say 5 miles, and it's HOT, then that's the deal.
I would suggest, jacking up that wheel, then wiggle (violently) in/out (6:00-12:00 positions) ...and do the same at 3-9 O-clock positions. If it feels tight, remove the wheel and put some oversized nuts (which fit over the studs) and lightly snug your lug nuts on. then put a dial indicator on the rotor. Then you'll know for sure if it's the rotor or not. Even a Harbor Freight dial indicator is perfect for this job. I never call a brake job done until I put a D/I on the rotors and they're less than .002". It's not uncommon to get rotors out of the box which are warped (yeah ...happens fairly often). In fact, if you're doing it, I'd put the d/i on your hub face just to make sure you didn't accidentally warp it hammering off the rotor. I doubt you did, but only takes a couple minutes to check it.
You did clean the rust off the outer face of the hub before putting on the rotor, right? Check the rust where the caliper slides. As rusty as yours looks, the caliper might not be moving freely. I almost always have to file rust off caliper surfaces, and the spindle on my older vehicles (where I live). And apply some lube to those areas.
Hope that helps.