I agree with some of your assertions and the overhaul thrust of the above the above except:

3) Parts of North Africa was part of a Caliphate controlled by some Arabian ruler and some percentage of the soldiers were indeed from North Africa.
4) Colonialism was driven by the need for resources to supply raw material to power the Industrial Revolution. There is no proof that Africa had invented something similar to the Steam Engine and by the way: when I speak of Africa I do mean Sub-Saharan Africa. This does not mean Africans could not have invented the Steam-Engine had the need arose but  there was no need for it at that juncture. What came out of the Egyptian Civilization is too  complex to discuss here. Egyptians however do not consider themselves African but Arabian.
Most importantly: from about the 15 century onward, through sheer necessity; certain European nations develop technologies that give them competitive advantage over Africans. So I guess we are generally in agreement.