After having a look at your videos and being pretty impressed by what you’ve come up with, I have a few thoughts to share. For me, a guy who is rather limited in rigging skills, I would find this plugin a lot more attractive if you could add just a few items that would help me save time.
With your current rig I would still need to add in rigging/controls for eyes and all that entails. Would it be possible to add the bones and controls for eyes and maybe even go further by including some actual eyeball geometry?
Maybe another option would be to include some type of cartoon eye rigging/controls/geometry?
Another thought, how about including some amount of optional rigging/controls that would allow for a character’s picking up of an item.
Hope you don’t mind the suggestions, just looking to provide some input that might help make your item more attractive for the low level riggers such as myself.