What do you mean by..... All of that? Are some enemies level based, like they're always as tough no matter what level you're on? How about things like the Dark Brotherhood, are they level based?
In Morrowind, creatures are not level-based, their stats are fixed. However you will still encounter stronger types of foes on higher levels, except at unique locations where specific creatures are placed and not creature groups. Items also are not level-bsaed, which I rather enjoy. I mean, Skyrim is not that bad since at least the items level with you (though does it make sense that a sword gets stronger? 0.o), I hated how it was in Oblivion about the artifacts, you could get stuck with a low-level artifact that would become useless on higher levels.
The Dark Brotherhood in Morrowind: Tribunal is just like the creatures, there are several different ranks among the assassins and your level will determine what kind of rank you will encounter, but the single ranks have fixed stats and equipment. But once you install Tribunal, you wil be targeted by them no matter your level, unless you report the attacks to a guard which makes them stop (I wouldn't, their armor is great, and expensive ;) )