I just came up with a system for unlocking anything you customize your character with, I call it the Challenge Tree System. There can be some starter challenges, once you finish a challenge you unlock more challenges that get slightly harder and harder, it continues till you have pretty much a big tree of challenges. Each challenge gets you armour and whatever ells you can customize with(armour, armour accessories, voices, maybe even assassinations and more). There could be challenges for campaign, multiplayer, firefight and maybe 343 will have a new mode to.
This way getting armour will not be the main point of multiplayer, multiplayer can be skill full again with proper ranks. You will still have bragging rights as well.
Maybe 343 can make it so they can add challenges with more customizing accessories monthly.
Even if you don’t have XBOXLive you can still finish the default challenge trees.