Number 2. The axle bearing are contained in the carrier assembly. Just because you remove the axle you do not have to replace the bearing if they are good. IMHO I would replace the swingarm pivot bearing if you remove it. They are easy to damage and hard to get at. Search the old posts for other peoples pain with swingarm removal.
Number 3. There are no bearing in the forks, they are in the front hub assembly. they are easy to get at and replace, so I would not do them unless they are bad
Number 4 The Head gasket is not a paper gasket. It is the gasket on the top of the cylinder. If you are having leaks around the covers on the top of the head, then those are paper gaskets. I have measured the thickness of different gaskets from a gasket set, and there are differences. I would use the right one. I have read about people using cereal box for side cover gaskets in a pinch, but I would only do it in a emergency (usually a in camp repair where you have to make due with what is on hand)
ATCnut
82 185s - sold
83 200x (hopped up)
84 200x (stock)
84 70 (lost this one to the DMV)
85 70 (soon to have lights, a foot brake, and CDI ignition)
84 200es (parts trike) - sold
85 350X (the best)
85 350X (siezed motor, dream of a poweroll kit someday)
85 250sx (frame was trash, got parted out)
86 250sx (the tractor)
86 250sx (a nicer tractor)
86 250sx (an even nicer tractor)
87 200x (parts trike, its really rough, a dog was chewing on it for a while)
87 250es Big Red (the tank!!)