Crafting weapons should require a sample of the weapon desired that would be consumed in the process (similar to how schemtics now work). It would make sense that you were repairing/upgrading an old gun rather than manufacturing one out of scrap metal and duct tape.
It would also make more...
The optimum perk system and XP gating settings will be different for different styles of game-play. A perk system that forces specialization might make sense in multi-player team play, but not in solo play. Likewise PVE and PVP play would likely have different emphasis with various traits being...