Re the custom races, as in Oblivion, some custom races (xivilai, golden saint, mystic elf) wouldnt fit the story and i think that's why nehrim is the way it is.
Re choices and consequences, i havent played that long yet but i really liked the part in the abbey where i had to choose between the boar hunting or the goblin(?). though i agree it could probably do with more choices (witcher style).
RE: Custom races. Well I'd have to disagree there. Written right you can make ANYTHING work and accomplish the same result. see my example.
RE C&Cs: Yeah it does slightly better in oblivion in that regard, but some things just annoy me that I couldn't do it another way (like I said, the slave thing.) Maybe I'm just too much of an Integration: The Stranded Light fan.
A little list of Things I'd hopefully like to see conversions of in the future:
LAME & Race Balancing Project: Like I said I'm working on a conversion for the later. It has a few flaws, namely that voices for the xivilai no longer work, summons don't work, andt unless you use Archive Invalidation Invalided (which itself poses the problem of the Nehrim logo on the load screen being replaced with the default Oblivion one.) the only way to get the skins / models for the Aureals/Mazkens Bone arrows, and Memory Robes is to manually extract them from the Shivering isles BSA (and no I do not have enough experience to make a program/script that does this automatically.)
LAME however I have no idea, but I would assume it would with some moderate/heavy modification (for starters all the merchants/leveled lists would have to go and be replaced with Nehrim ones.) Since it not only leaves the unused spell effects but also opens up some new ones.
Integration I didn't list cause it's a quest mod and it wouldn't make any sense.
Supreme Magicka: See the note on LAME.
Exnem/HEGC: I'm not sure weither or not these really work, but I'd really like to see something tailored specifically for Nehrim.
COBL: Yeah I know what your thinking. "COBL Ingredients in Nehrim would make no sense!" well... no it wouldn't. But remember: COBL is more than just Ingredients.
Fearsome Magicka: Now how cool would this be? Like someone mentioned, Nehrim seems to have the same useless magicka problem that Oblivion does. Of course, it would have to be changed a bit. Unlike with the oblivion version you can't just have everyone and their brother and their pet spider using these, and you'd DEFINITELY need a new spell merchant.
Midas Magic: Would no doubt require some heavy/moderate modification to take out the oblivion references, but it could work. Storywise it wouldn't be a problem, as it doesn't make any sense in Oblivion anyway.
To the OP: make a list please. Actually two: one for mods that work, and one for wishlist mods