My thoughts on the list so far:
1. I would at least flip Woodcutter and Great Hall, and maybe put Woodcutter above Develop and Great Hall below Chancellor. Woodcutter is a "terrible" card, but sometimes it's the only +buy on the board, and when it is, it can be a complete game changer. It's sometimes the last piece that turns a kingdom from BM into engine (or at least from a BM-hybrid type deck into an engine deck). Great Hall, on the other hand, very rarely has much impact on the game. Sure, it rarely hurts your deck, but the benefit is also very small. It's not even that great with the iron cards. It can build up a small lead, but that's usually not worth the trouble unless you want the Ironworks anyway; and in that case, you want IW to pick up whatever other $4 cards you wanted, not GH's. And actually spending $3 and a buy for one point and a chance to hit it with Ironmonger is a lot of trouble to go to for not much benefit. Develop I still don't really understand, so it's possible I'm underrating it, but it seems very situational; even on the boards with good cards at each price you want to pick up and top-deck, it's a terminal one-card trasher, which means you're giving up most of this turn's hand.
2. Fortune Teller is underrated. I think this is generally because it's hard to actually see the effect of the attack. According to Geronimoo's simulator, Fortune Teller-BM only loses to Militia-BM by 42/52/6, and Militia is considered a great $4. Of course, BM is not a good comparison, since attacks generally encourage engines, and other cards may offer better responses to FT than they do to Militia (on average). Still, it gives a good sense of how much the attack hurts. I had Fortune Teller at #24; it's not great, but it's not as bad as people seem to think it is.
3. Sage is overrated. It can be good at the beginning of the game, but it becomes worse and worse as the game progresses (maybe it gets slightly better early on, but in the long run it gets worse). It shouldn't be above Trade Route, Loan, or Smugglers.
4. Loan is underrated. It's a pretty decent non-terminal trasher, and it can't be drawn dead either. The existence of Forager makes it look pretty bad I guess, but Forager is outstanding. Loan is not a great $3, but it's decent. I had it at #21.
5. Masterpiece is overrated. I don't know where it is yet, but we should have seen it by now. I had it at #27, which is maybe low, but it's a very dedicated Silver flooder, which means if you go for it at all, you're probably not going to be seeing your other kingdom cards very much. Most of the kingdom cards are "better" than Silver, though that's not quite fair because you would usually rather be flooded with Silver than with X for a random kingdom card X (i.e. kingdom cards generally prefer to connect with other kingdom cards, whereas Silver is just money that can come up anywhere in your deck). Still, it's not often that the other 9 kingdom cards don't provide you with something better to do than flood your deck with Silver.