Matthew -
I was in 4 countries (Ghana, Togo, Sierra Leone and Liberia) and felt completely safe in Ghana and Sierra Leone. Togo is largely fine, but you need to take precautions, and Liberia to me did not feel so safe.
Everyone in Africa has a mobile phone and there were even billboards up advertising 4G, so at that level Africa is up to speed.
Ghana is completely developed - shopping malls, good roads, decent water & electricity and all that kind of thing, but the other countries in the region a bit less so.
Sierra Leone particularly is a complete mess - nothing works. The roads are just mud, and the buildings in terrible shape. The people were great, but it has a long, long way to go to become a functioning economy.
Much of Africa has improved enormously in the past decade, largely due to better government. And then it becomes an upward cycle - better govt promotes business, which improves incomes, which means people spend more and stimulate the economy. We're seeing that in Ghana, and starting to take place along the coast, but for Liberia and SL it will be another generation before people really start to feel an improvement is my guess.