So we can /skin or press k to apply skin, but if the server doesn't have the mods, then your skin only visible to you and anyone else that have installed this mod too.

Is a good mod. Please add that

Yeah, it's on my todo list, however, I cannot promise anything, I guess it will be implemented with #12

Oh also, if it support client side mod too, then is it possible to /cape? (work ONLY in singleplayer if it cant in multiplayer) just like #21
Oh you already mention it lol