In a Province game, Thief is good only when you're playing an engine and need to slow down an opponent who's playing a trimmed money deck (if he still has all his Coppers Thief is pointless), and possibly with FG or Harem, but I doubt it.
Coppersmith (preferably in multiples) is good only if you have a way to somewhat reliably draw alot of Coppers and have some source of +buy to go with it.
Neither condition is met here, so I would completely ignore both. I even think Thief actively hurts your deck here, in the sense that I expect a player who starts with a free Thief in his deck in addition to his Coppers and Estates to be the underdog. That may or may not turn out to be true, but Thief is certainly worse than Silver.
I agree with Awaclus that opening Fortune Teller/Silver is best (getting Stables on $5 and Golds on $6), though I'm not at all concerned about Embargo: you can play around any one thing that he Embargoes quite easily, and if he Embargos multiple things that means he has wasted valuable early purchases on Embargos, so you're way ahead already and the Embargoes hurt him just as much because there's no alternative way of gaining stuff, so the only workaround is only gaining important stuff when you have Watchtower in hand, which slows him down even more.
Also, your execution seems really inconsistent: on T14 you get your first Duchy for $7, but then on T15, after triggering a reshuffle during your turn, you get another Stables for $5 and on T16 a Gold for $6? If you think you need more Golds and Stables you want to get them before the Duchy, especially if you expect to reshuffle between the Duchy and the Stables/Gold buy.
And all your Shanty Towns should have been Silvers. Well, one or maaybe two is fine for the draw, but you really went overboard on them and you didn't actually have that great of an economy.