1987 300D possible vacuum pump fail?

[Docfranco]

I have a 1987 300D, I've replaced the head, and was about to sell it...a possible buyer came to drive it and noted a few problems. I don't have much experience to compare to so I was unaware of the shortcomings.
He noted
1. kickdown on the trans was not working
2. idle was rough
3. brakes require a lot of pressure
4. turbo appears to not be boosting well, it should have much more pickup

Before i begin to look at each of these, is the vacuum pump failing possible?
the door looks seem to work...a little slow but they work.