Well, cutpurse also provides +$2, while bribe is a straight attacker. It's also balanced by the 5 or more cards thing - this ensures it can't stack, unlike oldCutpurse which if played by multiple players would strip all the treasures from your hand. The main role of Bribe is a defense against single strong cards - e.g. possessions, treasure map, single early golds..., and as an in hand deck inspector, which could be useful with some strategies. Possibly it can do with a +1 action so it's easier to make use of. Compared with Sea Hag, Bribe hits this turn and hits much harder, but isn't lingering, and doesn't run out of usefulness in the late game.
Scientist I think would be a strong card for use in the late part of the game. With peddlers, it'd be terrifying, of course, but its main point is smoothing variance in draw engines. Stuck with 2 $5 drawers? Turn one of them into a village. Alchemists not turning up potions? Turn an excess terminal into one. You might even want to downgrade cards into estates to facilitate a baron. This is especially the case with games where players are laden down with duchies - losing 3 VP is a price I'd usually be glad to pay for a chance of getting a big turn. It's an insurance policy.
The difference between Freakshow and Gardens is that the cards you get are guaranteed to be useless. Workshop gardens for example relies on a good $2 buy (cellar, haven, pawn, etc) to grease the workshop engine, and at worst you are buying coppers which will let you get other stuff. Freakshow/Workshop leaves you possibly stuck with a deck filled with curses, and it's a fairly obvious strategy because it requires a large number of turns to acquire curses and freakshows, giving your opponent time for countermeasures like saboteuring, rabbling, or acquiring curses themselves.
