With regards to what sort of society Erik was planning, and how he might be able to make it appeal to people, it's worth remembering how he describes it:
"The sun will never set on the Wakandan Empire."
His plan is not for oppressed peoples to have the means to revolt within their own nations and then self-determine from there once they have secured power. He wants Wakanda to be the 'guiding hand' of a global superpower, and how far that extends is somewhat vague. So the question isn't merely one of whether of not people would be willing to fight for their liberation, but to then cede such to what they may or may not regard as a foreign power, but one that would treat them preferentially. That I think is a harder sell, though it would still appeal to some. It would ultimately depend a lot on context, as has been the case for Pan-Africanism in general.
