Mostly agreed, except for the "no way of knowing" part. In our games, experienced adventurers have some sense of the consequences of failure in their actions. Might be just a completely vague sense, but it is there.
Same here.
Now, I know you don't play a "gotcha" style as I believe you've stated as much before and you've mentioned that you've been a highly sought after DM for over a decade (paraphrasing here - can't find the actual quote), so that wouldn't jive with "gotcha" DMing. But, if the players don't truly don't know the consequences of their actions - or at least have some sense of them - then one is treading that dangerous ground of being accused of "gotcha" DMing.
Same here.
A player can always ask "can I tell what happens if..." and I will make sure the the scene is clear and possibly give an appropriate skill check which reflects their experience as an adventurer. However, they don't get "spidey sense" unless there's a rules justification for it. I don't do this to play "gotcha", but sometimes the unexpected happens.
Sometimes there's just no way to know what's going to happen if you push that big red button. To me, that's part of the tension, and the drama, of the game.