No game NEEDS to have randomized elements, I just like them that way. Much like I really only like strategy games with RANDOM MAPS...just a very weird personal quirk.
Oh, definitely. I understand. I seriously thought the campaigns in Heroes of Might and Magic 3 were rather awful, but the random mission generator was brilliant. It's almost like the campaigns felt like a tutorial, whereas the "Everything and the kitchen sink" nature of the RMG made it feel like each map was a complete... I dunno, experience?
But as I said, this is a different sort of game. EO is an oldschool dungeon crawler and an important part of these are the adventure gaming and puzzle solving elements that come up. EO didn't have as many as, say, Dungeon Master (which Needs. A. Goddamn. DS. Port. Now) but it still had quite a bit.
Also randomized dungeon crawls worry me in that they might end up too much like Daggerfall :(
One way to do it might be to have a few randomized filler floors in between each set floor (Sort of like how Dragon Warrior Monsters 2 had both randomized and non-randomized worlds). Arena was still very random but unlike DF, it had certain floor paradigms that you'd either see in different dungeon types or at different levels, which helps a lot too.
Also since you mentioned Shiren, I'm sort of WTF at IGN's review. They mention how the exit to a floor is sometimes spawned in the same room you start in, and this gives you no incentive to explore, but then they also, I believe, complain about it being too hard and you not having enough items. Er, derp? LEARN THE GAME, SON.