Okay, more fleshed out comments:
Scholar seems a little weak. Peddler is good at , and this costs . That's significant, but not a huge price drop. The problem is it loses it's power too fast. At all 5 copies will empty pretty quickly, and at only inquisition is easily picked up. Once enough people get Inquisitions then Scholar is really bad.
More later.
I don't think your opponent should have to buy a card to stop another card from being overpowered. With Tournament, that card is Province, which your opponent was probably going for anyway. I guess this is more like Young Witch, in that it's power can be reduced by your opponent buying another specific card. But also keep in mind that there's only 5 Inquisitions. You can get at least a couple of them, so there's not very many out there for your opponents to maybe have in their hand at the right time.
And also what if you just buy 3 Scholars and then stop? Your opponent basically has to buy a couple Scholars and a few Inquisitions just to stop your Peddlers from working. And Peddlers aren't all that strong that you want to buy a bunch of cards to stop them; but being able to buy them as your first 2-3 buys sounds like a really fast start.
The fact that there are only 5 Inquisitions is indeed something that bothers me. However, if your opponent only buys 3 Scholars, well, then he only has 3 Scholars. That leaves two for you. In a way, skipping the card for other players to pick up auto-balances it. You go full Scholar, my Inquisition will hit you. You don't, well, then you get less out of them. I made Inquisition chep to assure stopping Scholars has little opportunity cost, but the concept is still rough around the edges, i will admit. Maybe costing Scholar at $3 already solves the problem, or maybe i can find better ways to have Inquisition stop Scholar. It could be a Duration card and Scholar could check for Inquisitions in play - that would allow any Inquisition you manage to play to harm Scholar, not only those in your turn's starting hand. There might also be more room for interesting effects if Inquisition is a duration card. II'll think about ways to improve this concept.
About the problem of having to buy a card to stop other players - i feel most split piles have that problem, because the cards push each other and you can't let, e.g. Catapult stay uncontested. If you do, you end up with a kingdom where one of the piles is suddenly much more useful to your opponent than you. If you are not fast enough to get your share of the first half, you might as well skip the pile entirely - which makes 5 cards you can't contest without paying much more opportunity cost than your opponent. Unlike Rocks, Inquisition doesn't suck if you have no Scholar - in fact, it's better the fewer you have. So yes, using Inquisition to stop Scholar is kind of the concept, but i agree it's probably a bit unbalanced as is.
By the way, we played with Scientist today, and as its play effect is pretty much better than Stables, it seemed very strong. Maybe i should make the token optional and skip the coin part, i don't know.