In v6, the Dev version, aiden added free runners which stop fall damage and have step assist. I'd you ask him to put a speed boost on them he probably would
Do they improve jumping as well?
My request: the ability to fill a balloon with Hydrogen,
with expected results if it is set on fire(or if the one holding it does). Now, this may seen evil and mean, but I also request that zombies occasionally spawn with balloons. Also a way to fill balloons with other gasses(forge fluids that are lighter then air and not hotter then a certain cap), which would also be added to zombie spawns. Thus, we can get zombies with balloons filled with smoke, hydrogen, O2, but also gasses from Emmasher's mods, namely GasCraft(deadly neurotoxin balloons, ho!), and killing zombies can be more "fun" if you destroy the balloon they are holding first.
Also if we can hold balloons in our hands, then we could hit someone with one, yes? That should do a ton of damage to the balloon if they are on fire, have the thorns enchantment active, have any sort of thorns potion effect, or if they have a static charge. Oh right, with your helmet off you should be able to hold right click with a balloon in your hand to rub it against your head, doing a bit of damage to the balloon, but allowing you to get a tiny bit of energy, which is discharged into the next thing you right click with an empty hand, if you do it quick enough.
Also wool socks(made like boots from wool, bonus points if they are colored if made from colored wool, double points if you can dye them like leather armor) while rubbing them on a carpet(sneaking on wool blocks or carpet blocks) generates a bit of static charge.
With enough charge you can generate a bit of power, or activate things like redstone does(so with enough charge you can right click a iron door and it will open for a bit, or a TNT block will ignite).