For me it really depends on the game, the studio, and the publisher. I preordered Firmament because Cyan has a good history. I might also pre-order a digital game if I think a game is particularly novel, or if I think I’m going to like it pretty much regardless of the reviews (e.g. I like the franchise it’s from/ties into), the last reason is if there’s some kind of in-game incentive to do so (e.g. pre-order and you get some in game minor boost/cosmetic/whatever) but that’s really only a minor consideration.
Not yet or at least not badly. I have respect for people who have been burned to make their decisions but I also target games/publishers that I already trust. A game from a company I’ve never heard of will probably not get pre-ordered.