Everything is centered around gathering resources and using them to customize the functions of your weapon and omniframe. There will be a very straightforward recipe system and "nudges." Nudges are used to take a base weapon recipe and nudge its stats to favor what you like: reload time, ammo capacity, and other factors yet to be nailed down.
Like Diablo II, there might also be a way to "gamble" on improving an item. You could combine resources with alien artifacts you have found to bring to a NPC who can do R&D and tinker on your weapon. This will result in slight improvement to crazy good improvement or new weapon effect. Its a great way to have a resource sink in the game too.
For cosmetics, we're going to (where we can and still makes okay sense) separate cosmetics from functionality. Functionality is what you play and earn from skill/time. Cosmetics is what is sold to keep our servers afloat and pay for CPU and bandwidth. Even though we are charging up front, that doesn't cover the costs of running online servers for very long, and we'd rather the money go into future expansions.