Your thought on how people could improve steemit and add value to it is a great one.

I think it is really easy for one to actually add value to STEEMIT if they can add value to their lives. You can't give what you don't have and like you clearly said, a person who isn't a good speaker cannot be a good vlogger and as such cannot add content to the blockchain through vlogging. If people can find their niche, it will be easy for them to do what they have to. This is my personal opinion