I got rear brake discs replaced last week in our 2000 Acura 3.2 TL,
because the old ones were rusted very deep (at least that's what the
mechanic said).

I see a light rust on them already, as well as on my front ones which
were just machined.

Is this expected? There is none on the area were the pads rub. I've
looked around at other cars, and don't see such evident rust. Could
the discs be bad quality? Hae said they were original and cost me $ 60
apiece.

Also, I can sense a vibrattion when I brake to a stop, which hasn't
gone away even after 10 days after a new set of pads and rear discs.
Bad alignment or is this usual behavior for new pads?

Thanks