Taking up image slots makes it extremely incompatible with a lot of things.
Slot 0 is almost always a weapon. That cannot be used. Slot 1 is used for things like the second part of a weapon, like Guns Akimbo. Slot 2 is used frequently for other effects, for example, the Aluminum Bat's double jumping, and others. Slot 3 is used up by pain effects.
Compatibility is a two way thing. I understand slots 0, 1, and 3 being reserved because they are used for default stuff, but add-on makers should use a simple loop to find the first open slot not used by the default stuff and use that slot.
What do you mean by "limit player's to a "Chell Appearance"? You're running under the assumption that the only appearance on that playertype will be in the images seen so far? It's completely feasible to make a playertype color-able and decal-able. Yes, yes it is. Yes it is.
It just looked like the maker of this was going to have it be a very limited look, but I've never considered the use of node colors. I don't think decals would be possible, because they are controlled by the engine as far as I know, not scripts. The only possible way to script in decals would be through the setSkin, but that is very limited, as a model can only have one skin-able node (Unless Badspot changed that).
And I still think you don't understand the redundancy of re-making the default player type just to add boots to it. There's a lot of animations, and the new model would be inconstant with the default one.
