You said: “I think this is the core of the issue: The question of what (Afrikan) language to choose or adopt (at the "expense" of other ones of course) in an Afrika that is a sea of many languages. There are so many languages -- (or would one say ‘too many tribes’?) -- in Afrika,… “

“… and I personally know that Lingala, Swahili, Nyanja and other Afrikan “languages” -- (actually simply “dialects”) -- fall under this category of “vernaculars”. I believe such languages are the ones that could provide an answer over time, the ones that could easily qualify as potential choices to be considered for initial “officiation….”.

Yes, for instance, a vast number of African ethnic groups enjoy Soukous which is usually in Lingala. The Lingala expansion could be developed from Western Congo to all direction in Africa with music! However, many Africans from Central, East, and other parts of Africa will still be dominated by Swahili speakers, mainly of Nilo-Saharan origins.
The Lingala and Sawhili could become the predominant languages in Africa. But like you said our languages and cultural differences are so vast, it is clear that Continentals and Diasporians population could be dissatisfied with the Lingala and Swahili. Once our Panafrican movements will create a United States of Africa [ a Black Super Power greater than Western European countries (smile!) ] what common language for the Africans throughout the Diaspora will we use?

How to merge the incredibly diverse peoples and culture of Africa????? Tribalism and border issues are a major bar to the success of such a venture… although one of the biggest factors which led to the "cultural" success of the United States was the common language factor (uhm..).

B.K