Accord Euro

Hi
Recently bought a 2005 Accord Euro - Australian compliance.
Had it less than a month and have notice a couple of things that I would
like some clarification on:
1. A vibration occurs in the drivers side a/c vent. It is not persistent,
but seems to happen generally when taking the foot off the accelerator.
2. I purchased the car with after factory tinting. There is something near
the door latch that is scratching the tint/glass (on the inside). The
passenger side window has a "mark" that goes the height of the window,
almost dead straight. The drivers side window is actually "scratched" (well
I think the tinting anyway). There are about three scratches about 1-2" in
length. Two of the scratches are about 2" apart. The other one slightly
below one of the others.
3. I have never driven a Honda or a VTEC car for that fact before this car.
I have noticed that when maintaining speed, the car accelerates a little
almost like it is on cruise control. Is this normal? (6 speed manual).
Any help on these would be appreciated.
Thanks
Dominic