Did you get the rotor on flat against the mating surface? Did you torque the lug nuts the same. Either can cause runout on the rotor. Runout is when the rotor disk doesn't rotate true and acutally wobbles. You'll get uneven wear on the pads. Even a small amount of runnout can result in pulsing brakes and half the brake pad life.
The other thing to do is make sure the pins the caliper rides on are not corroded and lubricated well. They come from the factory with almost zero grease. Remove those rubber boots from the pins, clean them up or replace them and lube them well.
Also check the channels that the pads ride in, if you didn't replace the stainless channel liners, then at least make sure they are as clean as possible. Any crap in them will cause the pad to stick. Put some lube on the ears of the pads where they ride on the stainless channels.
Clean clean clean. Lube Lube Lube
Hardware kits with replacement channels and boots are cheap. around $10 at autozone.
Also try adjusting the parking brake - in a safe area, get rolling backwards (where you wont hit anything) and pull the handle up a couple of times until the parking brakes engage firmly. Might have to do it a couple of times if its way out of adjustment.
