Why not just order some gaffer tape online somewhere? It should be pretty easy to find.
Check out the tutorial section on the front page. It has pretty much all the answers you are looking for-------------
As to #2, the 4 rivets are for the "hero' suits. So Han and Luke only.
#3 are you talking about the hard armor strap or the internal straps?
#4 The original suits used hooks. I believe FirebladeJedi has a bunch of reference in the tutorials on that. See above link
#5 No reason you couldnt. I would think gluing the bolt would cause some problems, as a metal to plastic glue joint wont last too long. You should give it a shot, and post your progress! Many troopers are looking for innovative ways to build.
Centurion CRL says the knee piece is glued.