New clutch, now shudders
 

I replaced my clutch w/a OEM spec. Luk brand clutch. Only the pressure plate and clutch disk was replaced b/c the new throwbearing was damaged and I was in no circumstance to purchase a replacement.
To make a long story short, I replaced the pressure plate and disk and when I got in the car after assembly the clutch pedal felt softer, disengages @ a very low point in the travel, and shudders violently when slowly releasing the clutch w/minimal throttle. I have to rev slightly higher during take offs to minimize the shuddering.
My question is what is likely the issue causing this? Would this get better over time? Is this expected from new clutches placed on original flywheel that hasn't been turned for the new clutch? In the event that I may have contaminated the surface of the plate or flywheel, would the shudder gradually lessen? What could be causing my clutch pedal to feel soft and engage point to change to almost to the floor? Alots of questions, I know...

the shuttering sounds like a the flywheel needs to be resurfaced

5 days since replacing the clutch the shuddering has improved. I'm assuming new clutches need time to work itself. As for the engagement point, it's still very low.

Clutches are like brake pads, you always will have to resurface the rotor/flywheel. It will now cause for a bad wear on the clutch.