I would suggest that Gary Johnson and those like him of the fringe parties aren't going to be able to bring the breakdown of the greedy capitalist system. It's going to have to be through one of the major parties and it's likely the Democrats that are the most vulnerable. However, the perfect anti-establishment candidate doesn't seem to have appeared yet.
But rather than jump ahead that far, the elimination of Trump has to happen, one way or another. I think that your FBI and Mueller understand the grave danger of allowing him to continue for much longer. Maybe Trump will just resign instead of having to face the pressure that's going to be put on him and his famity?
I don't expect a 3rd party candidate to win the election, although they and their supporters can influence the platforms of the major party candidates. I try to get people to see issues as deeper than the absolutes of yes/no, black/white, and republican/democrat.