I chamfered the edges on the CF and don't have any wire issues.

A 4500 pack is plenty big, even for 8min races.

Mesh adjustment is cake. Loosen the 2 screws 2-3 turns, and rotate the can. Set the mesh just a hair wider than you normally would, then crank the mount back down. I find that the mesh always ends up a little tighter than I like, so I compensate for that.

Whenever you have a diff go, replace both gears. I also replace them before a big race just to be on the safe side. I also shim them tight. Any movement = death. Be sure to re-check/re-shim after you put a pack or 2 on a new set.