Yes and no, they do provided such service but they sub out to masonry workers.
Expect it to cost >$3.00 psf, cause they sub out.
Not necessarily if the clearance is enough, reputable vinyl installer will have machine for sanding door as this is a common problem for them. Expect to be quoted ~$80-100 per door if you opt for cheap vinyl, that's how they make money, try to bargain to ~$50-60 per door. =)
That amount u mentioned is the going rate.
Look online, can easily buy a rotary cutter for that amount and keep.