This threads title says it all, and what I am suggesting is that for pure cosmetics and nothing else, that we can equip a weapon of a type and have a 2nd weapon of the same type equipped as a costume skin just like you can do with armor and helms. Its really a no brainer, should be easy as heck to implement and doesn't effect gameplay at all.
That we have the same ability ingame to equip say a gun like the Sentenza (which like many weapons IMO look too over the top) and then equip a different looking gun like say the Valiance Valiance to have a Sentenza look like a Valiance, same with swords and bombs, the effects of the main equipped weapon would be retained since the gun flare, charge attack graphics ect are just a particle effect, so it would be a simple model swap while the original effects and stats are kept.
And so it isn't anything game breaking, but it would be an easy to implement side feature that would help this games great current customization a lot more.
And both myself and everyone else here can tell you half the equipment we use, we use cause of the stats, but they visually look horrible and out of place on our characters, and in a few cases the lower star more mundane designs of weapons and shields look a lot better then the higher star equivalents for eg.
And for balance in PVP (if it needs to be an issue)...and if it does come back then when you enter a PVP arena all equipped weapon and shield costumes are disabled temporarily till yo have left the arena.
PvP used to strip you of your costumes, while only Ultimate Brawl (which had a 5000cr entry fee before the weekend finale) allowed you to have costumes.