I like Ambassador/Steward as an opening, since it helps you get up to 5$ hands faster once your deck is thinned, and allows you to use 2 cards once your deck is developed. I think T3 you want Village instead of Silver since Silver slows your cycling and you already have some money from Steward. It also helps if you collide your two terminals. T4 you get both your Amb and Steward in the same hand, which is not ideal, but you play Steward to trash 2 cards, you could have done the same thing and given your opponent a copper if you had played Ambassador instead.
On turn 6 I would play steward to trash 2 cards and buy Silver or Village, which ever isn't in your deck. With such strong engine components you want to trash down fast. Additionally I don't think you would ever need gold in this set. You can get plenty of money from Minion/Merchant Guild. I think Ambassador can be nearly as good of an attack as Familiar, so I'm not sure you need a Potion on T8, but it does allow you to Ambassador Potion later which is always fun!
Overall, in this set, I want to trash down as quickly as possible, prioritizing returning 2 cards for at least the first 6 rounds. From there I want to build a deck of as many Minions as I can get for cycling and money, and finally round it out with Merchant Guild and Villages. I would think you could nearly get a mega turn here with merchant guild. I think with a tighter deck it should set up faster.