Really interesting post. Unfortunately I am too late so my upvote would'nt benefit you.
I really thought English is the main spoken language in your country. I was also not aware of the French influence on Nigerian English.
Language diversity is beautiful but on the other hand makes life more difficult in a united country. It is the same with the whole world. We actually need a common language, which brings me to Esperanto, the language createt more than hundred years ago. Nowadays English serves mostly as international communication tool, but Esperanto would do much better (if ie UN made the right decision). One day, I am convinced, we all will have a common auxiallary language, either a modified and simplified universal English or an artificial language like Esperanto.
Such an interesting topic! Have a nice day!
By the way, if you count Esperanto, you have one language more spoken in your country.