You know how in Halo 5 every armor had a variant like Recruit has Recruit Charred, and Recon has Recon RSO. If 343 decides to go that route they should have it where you unlock the base helmet/armor and have the option to change into those variants or buy them with req points. If 343 decides to keep Req Points they should be for cosmetic items only and no req packs where you get armor randomly, but the Ranking up system with the XP is fine but as you rank up every level or every other you should be able to unlock cosmetics and purchase them with req points. Basically like Reach and Halo 4 mixed up.
Feel free to use any of the existing wish list threads in General Discussion or Universe to talk about future Halo games.