There HAS to be an Affiliate program.
Twitch has proven by adding an affiliate program that both they and their streamers make more of an income. The biggest negative feedback to the affiliate program was by the Twitch Partners who felt that this detracted form their possible sub's. There is no evidence of this as all streamers have variation in sub's and that can not be tied directly together.
Affiliates would get the ability to receive "Embers", a Sub button, a generic contact for mixer support, and a little bit of advertisement form Mixer would hurt. (ex. Channel two which showcases one affiliate a day and does not provide an increase in sparks like channel one.)
Partners would still have a personal contact at Mixer, still get all of the same current benefits like the ability to make money from advertisements, game/features purchased through their channel, sparks and everything else they already have.
This would allow smaller streamers to still make advancements as streamers and also increase income to Mixer. As an example without a feature or Channel one which is filled with lurkers farming Sparks almost ALL partners average 15-30 concurrent viewers throughout their stream.. This means they average (12K-25K followers) less than 1% concurrent viewers without the help of mixer. Where as non partnered streamers below 2k generally average the same if not a higher percentage. there is no fiscal reason as to why Affiliate would be a bad program to introduce. The only down side will be how partners feel about it and if Partners disagree with the program not only has Twitch shown it doesn't affect their partners, but it would also show that Mixer partners really don't care about growth of the community, but only of their channel.