2) Plates like the ones s&p sells work nice, i believe gmcwantsls1 has them or made some similar, not much to them.
3)yes it should
4) if you use the plates to change the location where the motor mounts, you'll either need a longer or shorter one. if you plan on getting some power out of it, go with 3" HD Aluminum at least. im going to use Denny's
5)the expensive answer to this one is Painless Harness($500) stand alone. the cheap answer would be to splice the existing 5.3 harness like allen and a few others did. that would require some dedicated wiring time.
6) you can make your own pretty cheap. 3" pipin and a K&N conical air filter will out-do the $200+ air intakes people sell.
7)it can be done in a weekend. just do some research and a little reading(tech/swap tips in the refernce section here) and it will go smooth. the thing is to anticipate the little hangups.

GOOD LUCK!!