GFCI receptacles

I have always installed my fans and lights on the load side of the GFCI. while this is not necessarily code required it is an additional safety feature which does not cost anything and gives you peace of mind.

I don't quite agree with you. If something accidentally fell into the sink while you were taking a shower, I don't see how finding your way out in the dark is very safe. The light fixtures aren't required to be ground fault protected, but in some circumstances special fixtures are required. (I.E. vapor proof lenses over tubs and showers.)

Going form the NEC, you are not supposed to connect anything more than receptacles on the GFCI. The reason is as stated in previous comments is safety. If the GFCI trips you need to be able to find your way out.

I generally regard the protection of the GFI as more important than the
"darkness` factor in residential applications.

I assume the resident is sufficiently familiar with his lavatory that the risk
from darkness is minimal, while if a switch can be reached with wet hands,
GFI protection is appropriate.