It's unfortunate that the dungeons were designed in that manner but rest assured that the devs absolutely learned from their mistakes in Castrum and Praetoreum. No future dungeons have long cutscenese in the middle of them.

As for your Crystal Tower run, you're going to find people rush the content whether you say you're new or not. You're doing things that are several years old but various items which are currently relevant get put in them to keep them alive. As such, a lot of people are running the Crystal Tower series each week again for an Aether Oil which is for the current relic weapon. These people have no desire to slow down because they just want to get it done. Unfortunately, the best thing for you here is to continue to catch up and try to be prepared for the new content when Patch 2.4 comes out. The easiest time to learn all encounters in the first few weeks after a patch when everone else is learning them too.