Alright, I'd love to help you with your problems... but they don't sound too common!

A/C... I agree with southern son, could be a vacuum problem.

As for the sunroof, what do you mean it gets stuck 3/4 of the way closed? Does it go real slow the last 1/4 of the way? Or does it completely stop? And the pop up feature will not operate...
I would replace the sunroof switch and grease the sunroof rails.
Hopefully that will clear up your problem.

Your passenger window must be off track or something. The only way to find out the problem is to take off the door panel and investigate. The door panel is not too hard to remove.

Good luck and keep us posted.
:p

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)