Helmet
Multiple attachments, Visor detail(visor cracks, Mr chief face, ETC.), Helmet effects(Helmet Fire colors, glitch effect, ETC.), Helmet coating(make the coating system for seperated parts), and Helmet details(shark mouth, blood, ETC.).
Body
Chestplate customization(Chest plate and attacment seperated), Chest detalil(chest gash, colored stripes, ETC.), Chest coating, Chest effect(inclement weather, pestilence, ETC.), Toggle knife, knife positon, knife type(Combat knife, Emile’s knife, ETC.), back accessory(backpacks, swords, Etc.) back accesory colors, and waist accessory(tail, grenades, ETC.).
Arms
Arm armor customization, sholder knife, arm effects(arm fire, glitchy arms, ETC.), arm attachments for both arms, equiptment position, arm prosthetic customization(Mark V prosthetic on Mark VII), lefty option, and arm detail(think back to Halo 3).
Legs
Upper leg armor customization, lower leg customization, foot customization, leg detail(think back to Halo 3), upper leg attachments for both sides, lower leg attachments(think back to odst), leg coating, equiptment position, leg effects(leg fire, glitchy leg, ETC.), and leg prosthetic customization(Mark V prosthetic on Mark VII).
General
Proper body type customization, techsuit, Effect(spawn effect, death effect, ETC.), starting animation, and all weapons/vehicles customizable.
If 343i did this it would be amazing. Is there anything I missed or you disagree about?