1. No, the geometry of older Campy derailleurs isn't the same as newer ones so you will need a more modern 9 or 10-speed derailleur to index properly. However, 9 and 10-speed Campy derailleurs will work with either 9 or 10-speed Campy brifters and cassettes. (Any Campy experts disagree with the above?) Shimano's rear derailleurs (except Dura Ace) are the ones that will work with anything from 7-speed on up brifters.
2. Yes, Campy (ISO) tapers are tha same and should work with any of their cranks.
3. Modern pedals should work fine with your cranks.