Quoting See4Ways:
Lightened flywheels make the revs raise when shifting.
does the clutch slip? you can't take someones word for when it was replaced. Take an hour to pull the trans and inspect it yourself then spend money if needed.
incorrect.
A heavier flywheel (I.E. stock) keeps the engine rotating due to the extra rotating mass. It also has a lot to do with low end driveability. For instance, take our stock flywheels at half-a-million lbs and throw on a lightweight aluminum unit. You'll notice not only are your revs WAY quicker, and likewise on decel. On top of that, you'll more than likely notice you also have to give it a bit more revs to get it going smoothly from a stop, ESPECIALLY if you arent running the puny stock turbo that spools stupid low in the rpm range. Thats largely due to the decrease in mass(which as i said earlier helps keep the enging rotating, in effect). Lightweight flywheels are designed with quicker revs in mind, so the engine doesnt have to work as hard throughout the RPM range, hence the increase in performance.
A perfect example is an F1 car, which has very, very little/next to no flywheel. Hence, why they rev so rediculously fast to redline, then back to idle.
Hope that helps.
As far as the OP, I'd definitely recommend both bleeding AND adjusting/checking your trow on your clutch pedal. There is a very detailed writeup on VFAQ regarding the procedure, complete with pics and step-by-step info. Start there first, and if it doesnt work at that point, then start thinking about tearing into the car to diag a malfunctioning clutch assy.
-Jake