Is it possible to recover a private key if I have 2 files of one encrypted wallet, but with 2 different passwords used and a list of all addresses used by that wallet, many used over a dozen times each? Passwords are 80% known, but I don't take that into account.
No, unless the wallet uses flawed encryption which vulnerable against known-plaintext attack or chosen-plaintext attack.
P.S. this tool (BitCrack) isn't designed to crack wallet's password.