With a size differential that great the dovii will probably die. Butti's are quite aggressive, and the Dovii is just too young/small.
Mixing africans and CA's can work, but it depends on what africans you're thinking of. Not only are their water chemistry requirements different, so too are their feeding requirements. There are plenty of vegetarial Malawi cichlids that can suffer from bloat if fed too much protein. Many CA's require a decent amount of protein, and it's tough to tell the little mbuna's not to eat the protein flakes/pellets.
I have mixed a few africans with CA's with great success. Just find one that isn't succeptible to bloat and isnt' too picky about water close to neutral pH. As far as aggression goes, many africans seem to be unconcerned about american cichlids, and vice versa (not always true for Butti's). I used to be able to keep peacock cichlids and/or small butti's with my midas...not now that he is full grown though. I have mixed JD's and Oscars with africans and all went well. In fact, you can see a blue african (would have to look up species name) in my avatar with my O's.