Efficient Algorithm for bilinear pairing on ECC
I realize this does not do justice to the breadth of your questions but as a starting reference, you may be interested in the benchmark times for various pairings implemented in the pairing-based cryptography (PBC) library:

http://crypto.stanford.edu/pbc/times.html

They reference RSA decryption to give a sense of time relative to a standard operation (although it isn't as useful as knowing a DL or ECC-DL operation). The main developer, Ben Lynn, also did his PhD on PBC implementations—the dissertation may answer some of your questions.