Hill Throw Out Bearing failure

Friday afternoon, taking the 512TR out for a short cruise, 77 miles since the major, 40 mph and BAM! a LOUD intermittent, then continuous metal on metal scream from the rear. 2 seconds later, half a clutch pedal, then no clutch pedal (pedal went to the floor without resistance). I immediately pulled over and shut her down. No leaks, inspection normal. Called AAA for a tow.
Then, sitting in the car, the clutch pedal feels normal and I can shift through the gears (engine off) with no problem. Try starting again - same noise.
During the major I disassembled the clutch pressure plate and cleaned the flywheel. The disc had plenty of material. In retrospect, I did not check the throw-out bearing or make sure it turned freely. I otherwise did not touch the bearing. The first 77 miles since putting it back together were perfect in terms of shifting and the clutch.
After breaking it down there was no visible damage except for a small nick in the bearing outer case, but the Hill Engineering throw out bearing was frozen solid.
Seals looked perfect. It worked well for 36,000 miles and I did not notice any noise except maybe a little rattle on start up.
So, a few general questions:
1. Any explanation for why the clutch pedal temporarily went to the floor?
2. Obviously a new bearing will be ordered, but is there any reason to replace the pressure plate or clutch disc?
3. Should I even take the pressure plate off and, if so, what should I check for?
4. I don't want to spend $2K+ on a new clutch. Can my present unit be rebuilt, and, if so, can any clutch rebuilder do the work, or are there some special Ferrari-specific values that are needed? It's a Valeo pressure plate.
5. If the clutch is replaced/rebuilt, does the whole assembly, clutch and flywheel, need to be balanced together (car is not tracked)?

Thanks for any guidance. Have a Happy Mother's Day!
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Here are photos from the December 2019 disassembly.
Check the last photo. The larger metal tube (drive shaft goes through it) became dislodged from the differential housing when I was removing the bell housing and had fallen into the gearbox and had to be fished out. I replaced it in the differential but this seems to be an interference fit only. What keeps this tube from vibrating loose and falling again backwards into the gearbox housing, and will this do any damage (it can't be good). Any remedies, precautions?
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Actually the reply from Paul Hill was prompt and on point. In retrospect I should have checked the bearing for non-smooth rotation or probably just replaced it as a regular service item after 36,000 miles. The actual bearing in their early model clutch release assembly was the same as in the stock Ferrari unit. It was upgraded to a different manufacturer in 2011 (mine was a 2005 model).
Here is the reply from Paul Hill:
Hello James,
Thank you for your email.
All the clutch release bearings that we produced before 2011 used the factory SKF clutch bearings. In the interest of continual improvement we asked RHP/NSK to develop the clutch bearing for us based on the SKF bearing but using our specifications (uprated seals, grease etc) These bearings have been used in every CRB clutch bearing since 2011.
The area where the clutch bearing sits is an extremely aggressive environment and these parts are intended to be service replacement items and unfortunately the longevity of the unit has many variables to exactly how long they will last. (We have no recorded problems / issues with that batch number)
Hope that helps.
Regards
Paul Hill
My seals on the bearing assembly looked perfect and there were no leaks. I received my new Hill Engineering clutch release bearing assembly yesterday fro Daniel at Ricambi. Cost $430 delivered. Cost of OEM Ferrari part $1100+
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I agree. The mating surface of the bearing is smooth and I don't see or feel any sharp edges on the fingers of the pressure plate. I'll go over it with a scotch-brite disc just to make sure.
Is the bearing always in contact with the pressure plate and always spinning, or does it only spin when the clutch pedal is depressed?

 

That makes sense