I would have probably put a bigger focus on Library for drawing my cards.
The problem with Library as a card drawer is that, first, it's totally incompatible with any of the other card drawers on the table, and it's only really compatible with Fishing Villages every other turn. That said, if I had taken Library from the start... I don't know. It's a possibility. I've never really put together a Fishing Village/Library engine, don't know how they perform.
I took Torturer on the basis that it's not only cards/actions, it's a brutal attack.
Torturer is pretty counter-intuitive in such an ambassador deck, as your opponent can freely take the curse and send it back to you.
I definitely underestimated the extent to which the "Curses go into your hand" part of Torturer sets up a good Ambassador return. And I think that Phoenix played his Torturer choices very well, making good decisions about when to accept Curses and when to hand-size reduce.
That said, he only had 3 Ambassadors. One of the ways I felt a little abused by chance was the degree to which he (with basically 5 card hands until the very late game) seemed to have Ambassadors in hand whenever my engine fired. I knew that Ambassadors would return some curses, of course, but I felt like it was the classic "sure, your Chapel can trash Curses, but then it's not trashing other things" dichotomy where he'd end up spending so much time fighting off the Curses that his deck wouldn't be able to improve. After all, Ambassador is a terminal that doesn't add to your that-turn buying power.
Again, I really think that Fishing Village vs normal Village hurt me here. Fishing Village + Torturer on the turn FV is played only gets you 1 card advantage. FV on turn 2 + a Torturer gives you a 2 card advantage,
for the FV's that were played the turn before, but if you do draw more FV and Torturers there, you're back to only 1 card advantage on that turn. The point of a cards/action engine is to set up mega-turns, and the way that FV is better on turn 2 than turn 1 really compromises the ability to chain them together. If I had been drawing my whole deck or close to it in the mid game, I don't think his Ambassadors would have been nearly as much of a problem -- one or two Ambassadors of my own could have more-reliably returned the curses back to him, and ultimately that's a game I win -- if I'm Cursing him with Torturer + Ambassador, that's going to work better than him Cursing me with just Ambassador, and if his deck gets a little more bloated, then he stops reliably drawing his Ambassadors, especially with FVs to chain them (or he buys more Ambassadors and has buying power problems).