Well the file on entrants I think must have every living candidate as it has over 13, 000 celebs on it, and this year we have 487 teams so can only have 9740 different celebs at most. (And obviously don't, just see the Drop 40...)
Ah ok, xls confuses me (I'm the words guy not the programmer) but it looks like 3396 different picks, of which 2322 are unique.
The third question is beyond my knowledge.