Hi Did The Garage Change The Bearing As Well . As I Had A Gtv That When Driving At Over 5000 Rpm The Pedal Stuck Down. This Turned Out To Be A New Clutch With An Old Bearing Which Was Sticking In The Hole Between The Fingers Of The Clutch Cover
That's where Iwas going to head, If they only changed the clutch plate ofn the fly then yes the Thrust bearing and Finger plate may need to be done, if you've paid for a "Clutch Kit" replacement then ask to see the old bits (doubt they have them now), or get them to open it up and sort it, this is where the warranty of thier work comes in.
You mention heat is involved too (engine running for 5 minutes), that normally relates to sliping and the rancid smell so I'll ignore that from now.
So other possibilities are ,
Master cylinder, if the seals shift and this jams then it's going to be stiff or rough.
Flywheel, maybe a bolts come loose or the dampers given up.
Bent input shaft, the muppets have bent the input shaft of the gearbox in thier efforts to take short cuts when seperating the box from the engine and allowed the shaft to take the wieght.
If your lucky, it'll be a worn bush on the clutch bearing arm, the excess play gives you a rough feel, but doesn't explain the stiff operation.