Your valve cover gasket is definitely leaking. But, I doubt that it would make it smell like burnt rubber. And I doubt that you would have smoke coming out of your hood unless the leak was REALLY, REALLY bad.
Q: When you changed to the UUC pulleys, did you check to see if the tensioners were o.k.?
Another thing to check that leaks around your mileage is the cooling system. Have you checked your cooling system for leaks?
Imola Red 2004 330i ZHP, Sunroof, Cold Weather Pkg, Assist, Navi & Leather. Upgrades: Front & Side Clear Lens, Clutch Stop & CDV Delete. 10.2006-Differential Swap to 3.46! 12.2006 - UUC SSK, DSSR and Tranny Mounts (Red).