Solar,
Try an experiment for me. Pick a race that you have a savegame for. Open the CK and just, say...delete one of the racial abilities/specials and save the mod. Then load the mod w/savegame. Does it break for you? I promise if you uncheck the mod it'll work again.

Literally it seems anything as innocuous as removing a spell from the race can break 1st person view. I cleaned my mod of edits against the races and 1st person returned. I then made that simple edit above and the problem came back.
I would love some confirmation that it's not just me.

-MM
Okay mofomojo,
I tried this:
Opened CK, loaded Skyrim.ESM.
Removed the Breton racial trait
Saved making a new ESP
Loaded a clean (no other mods ever installed, Lvl 1 character) save game with a Breton
Looked fine in first person, went out to 3rd person, looked fine
Readied a spell, went to first person and I see the problem - I can see the spells glowing in my hands, but I can't see my hands or arms
So I don't think it's just you.