When it comes to pre boss cut scenes if there is plenty of time i don't see the need to rush or to expect others to rush. Sometimes it helps to establish you are new to a dungeon so people will expect you to watch the cut scenes. Not encountered too many people who are jerks about this i will normally purposely not cross the purple line before the cut scene is done if i want to watch it so if they want to be healed they will just have to wait. Had a couple of "go go go!" Tanks still who charge in without a healer and i just have to wait for them to wipe and waste time while they run back more so than would have been wasted waiting a couple of minutes for me to watch a storyline scene.
