Questing ?

OK, I wish the quest where you need an item to unlock a door were marked. I seem to run into a lot of them and never have the item or enough mats to make the item. My luck with RNG in these types of games has always been bad for certain drops. I end up just getting frustrated trying to farm for the mats.

What do you mean by marked? There are only the 4 rogue dungeons that need a skeleton key plus the Depraved Sanctuary where Salazar hangs out. For each of these you can get a side quest that gives you the necessary key.