Wailing Caverns: Dreadfangs should fear. (As in every dungeon or with any mobs in groups) the Groups mostly aren't linked, so that if a group, where 2 or more should be pulled only 2 mobs come. Endboss mobs should attack the disciple of naralex and kill him and then everything should disappear, so that you are fuck if you failed to protect him and can't get the drop quest of the endboss. Don't make stuff too easy... I think the blue raptors should call for help when they are near death, if I remember correctly.
Mounts: A lot of zones for example Booty Bay don't kick you off your mount if you enter. In Booty bay it makes actually more sense to be able to ride, because it is outside, so I'd actually understand, if you could stay on the mount, but then please make mounting in Booty Bay available, else it makes no sense.
Rogues: Don't know if this is actually intended, but my stealth is OP on NPCs... I can actually walk THROUGH them and they don't attack me. I skilled it, but even then... Pickpocketting should not be able with mobs without pockets like Murlocs, Thistlefurs, Naga etc, but it is... At least with murlocs, and that is wrong.
Collecting professions: With regard to veins or herbs being orange considering the skill level, the try should not fail in the beginning, but in the end. When the castbar ends it should tell you that your try failed not in the very beginning.
Remember: Blizzlike actually means "hard as fuck, timeconsuming and annoying" but not darksouls like...