I honestly thought it would be cool, that on your hotbar on infection, maybe at the far right. There would be a little zombie head, and you could click it, and have 3 custom zombie skins to choose from. Possibly these 3. Normal Zombie Ripped Shirt Zombie Female Zombie No idea how it would work, but just an idea.
Support. However it may be hard to choose which one. If it isn't possible or cyp and tanner just can't be bothered like usual, maybe make them randomized.
Neutral, hair length doesn't mean what gender you are. The current Minecraft Zombie skin is already quite neutral. If you want a change, change your texture pack.
Support but I think it should be a command. Like you type /skin (just as example) and you get a menu of some skins.