hi Rohit
with respect to point 3, NSDL has a very large market share of institutions (has almost 22 banks as its demat clients), while CDSL has more retail investors. however, pls note that the revenues are not dependent on value. if a promoter pledges its holding to a bank, they will hit the NSDL account of the bank, and thus the value share of NSDL would be higher to that extent. but the trades in the pledged would be miniscule, so NSDL does not earn any revenue from it.
further NSDL is the only depository mandated by regulators to service demat accounts for FPIs.
on point 1, a large number of unlisted companies have demat arrangement only with NSDL since NSDL provides cheaper rates. CDSL started following NDSL rates from last year. in the table shared by you, it can be seen that more listed companies are on CDSL platform.
no idea with respect to point 2.
hope this helps.