Wow, you guys are amazing, you want to offer advice when you have not done the job.
Its very simple that to do the job without a risk, you use the correct part.
If you use the wrong part, you have a risk of failure. The choice is yours. (I am talking about the clutch cover).
However if people cannot understand how two parts (flywheel and a clutch) and one is now a different weight, why they are not balanced then I cannot help anymore.
ITS NOT ABOUT WEIGHT ITS ABOUT BALANCE
The clutch is not balanced on itself, its balanced on the engine. (thats crankshaft, flywheel and front pulley). I cannot think of another way to make is simpler for you to understand.
CLUTCH ASSEMBLIES ARE BALANCED AT FACTORY,PRESSURE PLATE AS WELL AS COVER TO A WITHIN MANUFACTURERS TOLERENCES,FLYWHEELS ARE BALANCED so when you ask any supplier for a clutch they dont say you need to balance your engine up prior to fitting it in your motor
But its not just the clutch, its the rest as well, that is where the problem is, yes if you have more holes equally spaced on a circle it is still in balance with itself, but that is not the issue, it is not out of balance with other parts.
You will find out if you spin your engine to high rpms as that is when the balancing problems surface more.
TO WITHIN MANUFACTURERS TOLERENCES
Another way to explain is car wheels that are not balanced seem fine at low speeds, drive on the motorway and you see the difference.