Vibration!!!!

Please help with advice: I do not know if this is drive line or engine related....
What are the symptoms of a worn Center support bearing/housing on my 2001 740i. I have a vibration at around 2500 when accererating. I have just replaced the tranny mounts and engine mounts...vibration is better which was more pronounced at 1300-1500. This new vibration is a different one since replacing the motor mounts and tranny mounts. If i need a new drive shaft, is an aftermarket one acceptable with no vibrations? If so, where should i get one. I see them for around 400.00 but i have been told by the dealer tech that they will not balance correctly.
Also: When i jacked the engine up for replacing the engine mounts on the right side, i broke the hose from the secondary air pump. I taped it back together and was wondering if that would cause a rough idle after warm up? I get an occasional rough idle as well.

THANKS SO MUCH FOR YOUR ADVICE AND INPUT!