I think I would also have gone for Alchemist/Conspirator with Tournaments, so definitely open Potion. The $3 is hard, Black Market does not seem entirely wrong to me, although I doubt weither to open Workshop. There are several uses for Workshop, you may want to get a couple of Conspirators, but I would concentrate on Tournaments, and more importantly, if you keep Islanding away your green cards or Curses, the Alchemists will continue to draw your whole deck all the way to the end. An engine that can get Province+Island and sustain it seems good enough here. Note that you don't need a lot of cash without a good source of +Buy (HT is not a good source here, without actions, and you better race the provinces because if you lose too many prizes, you are doomed).
Followers is nice, but it actually only means a 2 VP swing, because engine-wise, the Estate is as bad as the Curse, so you can consider Followers to be something like +2 Cards, +2VP, militia-atack. This is pretty good, but a 5-3 Province split probably means more. If your engine is reliable, is maybe better to get Trusty Steed first for the actions or even Princess for the +Buy, which will clearly enable double Province turns (even a single double Province turn may give you the game).
So, in summary, I would open Potion/Workshop, get at least an Island and some Alchemists, and then get one or two Tournaments (by the time you have provinces to pair them with, you would probably be drawing most of your deck anyway). After that, adapt, esepcially when it comes to prize-picking, but if I win the first Tournament, I would get Trusty Steed, especially, if I have more than 1 tournament, because it can make you get Followers in the same turn if you have the draw.
BTW, if you are planning on getting 4 or 5 alchemist, and get a bad hand like CCEEE, pick up a Copper.
EDIT: I would have to rethink everything for 5/2 opening.
