Keyholes + tankful of africans IMO is a disaster waiting to happen... certain mbuna can cut up rough.. and keyholes are certainly too peaceful to be putting up with Africans attitude.. it is when these fish really mature and get the whole idea on territory and breeding, that will be the problem. Africans are an interesting fish, you can have all peace and harmony going on in your tank and then wham, something upsets the apple cart and all hell breaks loose... and often the weakest link gets popped off, IMO your weakest link would probably be the slow moving Keyholes..
I certainly wouldn't suggest to anyone that your stocking of fish is a good idea, however, it could work for you, I hope so :lol: