Does Protection from Evil protect against Fear effects?

Depends on whether the spell was given the specific descriptor - not always the case for spell-like effects. For example (all of this is from memory) the Bodak's death gaze was not prevented by Death Ward because in the innards of the game it didn't have the Death descriptor (or whatever it was, negative energy or whatever) on account of it being a spell-like effect and not a spell of the Death-descriptor variety.

Since we can add those descriptors, these should be called out as bugs where they clearly don't do what they should. For Protection from Evil, the if the kicker is not simply whetehr it is a mind-affecting enchantment but whether it is a mind-affecting enchanment cast by something evil, that would be harder to fix.