In regards to the ammo issues, specifically #1 and #4:
Unfired but chambered ammunition has the issue of the chamber's lip "shucking" the actual link to the rear of the round. Apparently there is a tool that you can use to link the ammunition, scooting the link to the proper placement on the round.
The excess dunnage sucks but is required for safety purposes during transport. I know that in the large Mk19 ammo can's you can easily double the amount of ammunition stored in the cans simply by unloading the cans, getting rid of all of the foam (and taping some to the strap the gunner sits on so you don't lose comfort factor) then linking the belts and backfeeding into the cans. You can safely store the ammunition this way.
Rough roads in afghanistan didn't cause a single round detonation with any of the linked and unpadded ammunition we carried on our HMMWV's.
PCI's. you backfeed your ammo into an ammo bag for a 240, not sling the boxes it comes in around your neck... same thing applies here. Every can on a hummer with a Mk19 needs to be broken open, de-foamed, and backfed.
As for the new weapons system stuff.. wonder if they can figure out a way to put that on a stryker?
I still vote for a GAU-13 and one big ammo bin.