Definately check the pedal height adjustment. However, the tech who installed the clutch should have done this. I'm not familiar with your vehicle, but I'm guessing it has a hydraulically operated clutch. If so I would check the master and slave cylinders to make sure they are not leaking. If you have black fluid in the resovior that's a good indication that the rubber is wearing out somewhere (true for brake systems too). If your mechanic put in a new pressure plate assembly sometimes those new springs can create added pressure on the old hydraulic system. Same thing holds true for a clutch cable... if a new pressure plate was installed sometimes this can cause cable stretch on an old cable (or a new cable that is "breaking in").
Another thing to think about if these problems don't exist is your tranny. Does your tranny have enough fluid? Is it in good shape and the right viscosity? Low or bad oil can cause drag on the input shaft which can cause hard shifting, especially when taking off. Hope this helps.
-Kevin
