In the games I run and play in (same group), we tend to have an overarching plot, but things move regardless of whether the PCs act or not in response to the plot. So there are 'rails'/plot-hooks in the sense of a path to take and ways to accomplish a 'good ending', but the PCs are free to ignore those.
I'd find an actual cutscene annoying, since the PCs should be able to interact.

For the dying NPC example, I think it's a case of making it so the plot-breaking info isn't revealed regardless of PC actions. The examples already given are pretty good.

For the ghost-quest example... that seems like poor writing. I get that happening in modules, and when I've run modules, I've sometimes gone OOC and told the players "Listen. It's a module. You kinda need to do this, so please go along. Sorry." Yeah, it's poor DMing, but otherwise some modules would have you tinkering away while the world ends. In my opinion, running a module has the trade-off of "less DM time to prep" but "more likely to have plot holes".
I've heard advice of there being at least 3 ways to get info to players or advance the plot, so that if the players miss one or ignore one, the others are still there. The ghost being the only route seems poor design. As does the door being the only way through.

All that said, I really love a good, mid-to-long speech by an NPC giving details. But then I particularly love the lore and metaphysics of a setting, even trivial, unimportant stuff. But, even if I'd be a touch annoyed, I'd accept my PCs breaking into a fight as the villain is trying to monologue and tell them the crucial detail for the real villain. I'd just have to have them get the intel another way.