1) It's as big as Twitter was back in 2011, and it's growing as more people use it.
2) I don't have an answer for this, because it would take considerable effort to get web designers to include mastodon links in their social media interactions.
4) Propaganda is almost nonexistent here in Mastodon.
@Memeghnad
3) Imagine 2 Monopoly boards where all the spaces are owned and developed. Twitter is the board where all the spaces are owned by one person, and Mastodon is the board where each space is owned by a different person. In the Twitter board, there is no place to go to, because all spaces have the same crappy rules. But on Mastodon, you may prefer certain spaces and stick around there, if not, it's easy to move to a different space.