Sure there was a great deal of interest by many parties and it did weaken the alliance but not as much as Serenity hoped. The alliance still controlled much and a lot of what they didn't private corporation in league with them did. The alliances is far too powerful for a single blow to destroy them. It might have sparked rebellion on a number of worlds but nothing organized and nothing that could not be contained.

None of the crew of Serenity but perhaps some of there contacts such as Badger, Patience, Niska and the like.

Possibly but yhat would mean Vix would have to be a passenger not a crew member. Though reading over her personality there doesn't seem to be a whole lot of room for friends. You could have two characters independant from one another but it doesn't seem likely that Vix would travel with someone without a reason.