I read through most of the posts before responding.
It is very unlikely that a master cylinder is causing the problem, and it is unlikely that a misadjusted push rod is causing the problem unless someone messed with the master cylinder or pushrod.
It is possible, but not likely that a bad wheel bearing is causing the problem. Wheel bearings generally make a lot of noise before getting bad enough to actually cause a problem.
A wheel or tire that is out of round either laterally or radially will cause a vibration, but not likely that the vibration will come and go and it will not make the wheel hot to the touch or bind the brakes so that is not high on my list.
A bad CV joint will make noise, cause pulling, or fling grease all over the undercarriage before it causes an intermittent vibration and will not make the wheel hot to the touch or bind the brakes.
If replacing the calipers did not change the problem, I would have guessed a bad brake hose.
I read that you are replacing the front calipers, make sure that the slides are free and coated with disc brake grease or anti-seize.
Where are you located?