As I understand it, there's only one regular assassin, and the random element is quite harsh. Plus, cities with mana have assassins, so the mages won't be able to hide anywhere if their only assassin is killed early in the game. It will be interesting to see how the mages will cope, especially with so many other non-mages around, but it's a bit strange. It might be worth trying for the sake of experimentation.
By the way, according to my idea, "Shot" doesn't count as a non-mage-killing action, so with a limit of "one non-mage-killing action and two non-non-mage-killing actions per turn," you can do both a shot and an assassination.
However, that's up to you to decide; you won't be the one sitting there and writing everything down; you'll be munching on popcorn and laughing at how we're going to mess things up.
Elizer Yudkovsky, "HP and the Methods of Rationality".
Мой ник транслитерируется по-разному, но я предпочитаю варианты Оот и Ооот.