To answer your question, yes it can become a big player in social media, but it still has a lot of growing up to do. Can it beat Facebook? Honestly, I doubt it, because they have such a big amount of money that they could buy SteemIt if they would feel threatened...

As for your 7 points, number 3 is an interesting insight that I have not noticed yet. Have you seen SteemIt posts starting to rank for any keywords? If yes, that would be quite an advantage for sure.