Custom roles and badges
I think twitch communities could get nice addition from having the ability to have custom roles with badges. Streamers could have some role and some amount of that role to give for people and because of course keeping this feature running isn't free it could be that if you want more roles and more people with that role you need to pay some small amount extra.
For these roles it could be nice to have ability to execute certain commands but this could be a feature that is implemented using twitch extensions (which to my knowledge could do this).
The main thing is that smaller streamers could have either the free role or be able have access to this feature as well as bigger streamers.