1.
More than four
2. In my Items menu

3. A large gun that fires a huge amount of concentrated energy, enough, in fact to wipe out the power in Midgar for an hour. It kills the planet!

4. The one from the case in the rocket
5. I shall name him Bob Terwilliger
The ultimate unanswerable question that I know the answer to!

In midgar, after destroying the sector one, mako reactor. What does the Avalanche graffiti say on one of the walls. (you can't see it, find out some other way).