So just to make sure I have this correctly now, your stock for your 29 gallon is now
-4 neon tetras
-3 serpae tetras
-1 rainbow shark
-1 horse face loach
-5 unknown African cichlids
-Possibly one male betta
If so, there are MAJOR issues in that tank, your new issue being the African cichlids. Not only can they be some of the most aggressive, nastiest cichlids (I had a female who ATE out all my community fishes eyes, two days fine, next day, everyone was either eye less, or dead, this was when I was learning african cichlids don't mix with community fish (i.e. neon tetras, horseface loach, serpae tetras), she was just a common "assorted african" petco fish) They need hard water, with a high pH. Hopefully this article helps you
http://www.malawimayhem.com/articles_chemistry_water_chemistry.shtml Most tetras prefer soft water, and the rainbow shark and horse face loach are probably okay with somewhere around neutral for a pH, I know the sharks aren't too terribly picky, but I'm pretty sure the loaches are more sensitive, as are the neons for sure.
You were concerned about your shark getting picked on, well depending on what species of African cichlids you have, as they get older and mature, there is a fair chance he will get picked on by them and not have the upper hand any more. It just depends on the territories you have, how large the tank is, whether males or females, if anyone pairs up, the sharks personality, etc. I rescued a rainbow shark that was in a 55 gallon with 3 pink convict cichlids, and his fins were all shredded and torn up from them picking on him.
How long has your tank been up and running with fish for? If it's not cycled on top of everything, then that's your number one issue right now.
Next is figuring if you want an African cichlid tank, or a community tank. Then rehoming the fish that won't fit, and getting proper schools if you go the community route, or adding more caves/territories and getting the water chemistry where it needs to be for African cichlids.
But have no fear, we are here to help you out