Hello All
This is my first post so please be gentle!!
I have moved to the other side, seen the light some might say. I have just replaced my Merc 190e with an e34 535i Sport

. Its a lovely car and although the Merc was really solid, this one seems even more so and the interior is on par with more modern cars. It is really satisfying to drive as well

, or was until..
I have been told that the clutch is slipping

and will eventually loose drive all together but I wanted to know if these symptoms sound like this problem:
Problem started when waiting at the lights, pulled away and there was smoke coming out the exhaust and the engine didn't want to pull, the idle was also erratic.
So I stopped and when I restarted it, it appeared to clear itself and drove normally for about 50 miles.
On the way home, it started to splutter again (no smoke this time), the car would jerk like it was loosing drive (felt like it was an electric fault), then it would pick up again, until the next time.
If I rev it from idle, the revs sometimes struggle and the engine runs rough (almost like its using bad fuel) then it picks up normally. Sometimes when I rev it, the revs go up normally but they then drop like I have taken my foot off (which I haven't) and then pick up again. Sometimes it idles and drives smoothly.
Sorry, the symptoms are hard to describe.
I believe the diagnosis of the clutch being faulty as correct but what I don't understand is why is it affecting the idle so much

? Surly a knackered clutch does not affect the idle, does it?? There are some whining noises coming from the clutch area when driving slowly tho and there is a distinct clutch type smell.
If it is the clutch, how big a job is it? I know in an e30, you need to take the engine off two of its mounts and move the gearbox, is it the same in an e34 (1990 m30 3.5i)? If all this needs doing, is it worth replacing anything else whilst it is all open
(such as engine mounts, selector bushes, gearbox synchro, other gearbox parts or any other clutch parts - master/slave cylinder, release bearing etc (car is now on 153k)?? As you can see, I know very little about clutch/gearbox setups.
I have also been told that a quick shift kit from a z3 will fit this car, is it worth fitting one of these now or are they not worth the hassle?? Has anyone got one fitted?
I am also looking for a specialist in the South London area if anyone knows of any. Any help or ideas would be much appreciated as have very little knowledge about BMWs (having only owned the car for a week!) so I am starting a new manufacturer from scratch.
Thanks
Rakesh