The kind of randomness I think is important

[Raestloz]

Not arguing with that. I was just trying to point out that randomization would not change things as much as the OP hopes that it would and only a limited selection of opponents can apply a meaningful difference. Changing the drapes and throw pillows only works so many times when the majority of the furniture is still the same.

I think OP wants less Left 4 Dead 1 and more Left 4 Dead 2.

You know, like, different path each time (such as the one in Toto-Rak, only everytime you enter one of the paths will be blocked permanently), maybe there are surprise monsters at the bosses, or during the whole dungeon run, where it can spawn anywhere anytime, make it do something interesting when it does, things like that.

It's boring to see the exact same pattern every single time. You know, looking at Amdapor Keep the first 5 times is great, but 125 times later I'd kill a moogle to just get it over with.