Ah man, i know I was supposed to help with this but I work like 60 hours a week lately and haven't had the time.
Anyway, here's my philosophy with making a historical map: You want a player to have some freedom in a historical map to play with the historical maybes and what ifs, and not to get stuck on strict historical template of a time period. At the same time, you don't want to delve into historical fantasy. So its a dangerous balance. Also, you need to have an ideal setting and round... when will this map reflect the historical situation you are portraying? I do all my maps presuming flat or no spoils and the bonuses are tooled to influence a player to re-create something close to the historical states depicted... for example, France is rather easily defended thus making France a player, as she was, during the German Wars of Unification. Her bonus value also reflects her power during the wars.. so essentially a player won't win on France alone, she needs to play aggressive inside Germany proper to win (thus doing the opposite of France's historical mistake).
All in all, I'd say you've got a good start and it won't be much to get it where it needs to be.
I like how the bonus system works, though really, I think there ought to be a sort of duel colony option for some of the places that changed hands, much like you've used with Egypt. Places like the German colonies could be duel colonies with Britain, Cameroon with France. This way, it gives a player to sort of build a little more like piece by piece and grow his empire. It also inclines players to desire Britain and France as there are more options available. This makes sense because Britain and France dominated the continent.
Ideally, you want Europe to be static and the conflict and movement to primarily occur in Africa... given its ability to yield easy and quick bonuses, I'd say you'll achieve this pretty easily. Though I'd recommend the European powers and Turkey be starting positions and deploy higher, say 5, to encourage static gameplay up north. It will be a good and true to history dynamic to have Europe concerned about the balance between continental and colonial obligations. You'll get some cool World War scenarios where if Germany knocks out France and France strikes back from her colonies, ect. I hope this map will be considered for WWI and WWII tournaments as well.
The only major gameplay element that I think you ought to add is a European one way attack on at least one of their major colonies. I'm thinking Britain to SA, Germany to German East Africa, Belgium to Congo, and Portugal to Angola. This way you get the Europeans able to land and conquer Africa, but Africans stuck in Africa... true to history and also makes some of the more harder to achieve bonuses, such as Portugal, easier to achieve. Maybe, even consider killer neutral ocean territories, giving European players a chance to make landings, ect. In fact, I think killer neutral sea territories would really liven up the gameplay.
And here's a list of some revisions you ought to consider:
Put in Zululand instead of Basutoland
Bechuanaland was South Rhodesisa.
Anglo-Egyptian Sudan ought to be one colony, as it was, and keep the duality.
There's better names for North and South Nigeria... but I'm at a loss... stay tuned.
You've got to put in the modern Algeria and call it Algeria... it was considered part of France proper and the primary French colony... scoot Tunisia to its place.
Equatorial Africa ought to be a duel colony with Germany... it was traded for Germany being ok with French Morocco.
Spain, Portugal, germany and Italy look ok save for their names.
Belgium might need a little more easily defended African territory, their weakness is their continental position.
For the two African neutrals... you might want to consider a duel bonus that only rewards with Italy and Italian Horn of Africa with Ethiopia and France with French Africa and Morocco.
The European neutrals... I don't like them. I'd be in favor of ditching them completely and bordering Italy with Germany. Turkey's threats came via through its colonies (WWI Mesopotamia and Palestine) and not through land attacks in itself (Salonika and Gallipoli). Given Turkey's proximity to Africa, I'd say there is sufficient threat to its power without bordering the European powers via the continent.
As for West Africa... I think you ought to add it in and put the labels in the sea. Guinea-Bissau, Gold Coast (especially with the Asanti wars there), Gold Coast, Ivory Coast... these would make great neutral starters and +1 bonuses. This reflects their richness in resources though precarious defensive position. It also makes a great way to increase a player's bonus a little by a quick land grab.
Lastly... impassables. I'd say increase them.