To some extent, democracy has suited some African countries even when poverty and power greed is severely witnessed among its people. This is because people have passed on constitutions that guide their will and what laws that particular country should perform. However, some countries do not allow free expression of human rights to its people, thus democracy has not been seen in such countries.
No, surprisingly, (I hope the government doesn't arrest me) Communism is. Despite the fact that the U.S. has villain-ized Communism, it actually works for small villages and tribes. I recommend you do some research, I think you will be surprised by what you find.
No, for the same reason Jefferson, Franklin, and, the rest of the founding fathers felt it best to go with a Republic. Giving the uneducated masses a direct say in the everyday machinations of the government is a recipe for disaster. The African continent would be better served with adopting a Republic form of government whereby elected representatives of the people serve as the people's voice. Of course, this only works if those representatives are bound by the rule of law with proper checks and balances in place.