I finished this campaign some time ago. Though I'm not a fan of Rexxar Campaign, never really liked it, I must say this is really good on Rexxar level. I played on 1.31.1.something, with Blood Death Knight, and didn't find any bugs which is really impressive. Amazing work you've done. Things you could change though:
-Some Forsaken models: Sylvanas(
Battle For Azeroth - Sylvanas), Nathanos(
Nathanos Blightcaller), Meat Wagon(
Forsaken Catapult), Gargoyle(
DarkwingBat_by67chrome.blp), Sharlindra and Melisara could use a different model, and all the quest giving apothecaries.
-Nethanos could use more Dark Ranger/Hunter like abilities.
-Imo Alterac map is too epic to be just the optional, it should definitely be a main and there should be a small forsaken base there(with the Tomb of Relics).
-In Arathi Highlands change the Syndicate, they are purple humans while they should be orange bandits. Also the Stromgard forces could be changed, remove Mortar Teams(too many dwarves already) change the footman skin to stromgard(
Captain, Footman, and Derivatives), change the riffleman with human archers(
FootArcher), change sorceress model(
HumanMage_by67chrome.blp) and replace the priest with chaplin. Replace Eldin with some Stromgard human.
-Change all red dragons in Arathi Highlands and the secret dragon map with black dragons.
-In the Hinterlands there should imo be a lot more Gryphon Riders, not just in the nest, but everywhere, especially where their chief is. Might be good if you changed dwarf footman model(
DwarvenMountaineer) to look more Wildhammer(only in the Hinterlands, not in Hillsbrad Foothills or Dwarven Cave). Also imo there should be at least an optional or even a main to deal with the high elves, and change priests/sorceresses giving the RoC high elven skins.
-Worgen tech tree could be a little more original, it's basically human. Maybe add Druid of the Claw and Warlock. Also not all units have to be worgen, maybe make priests and knights human.
-Would be cool to see more Gilneas lore heroes e.g Darius Crowley and Tess Greymane.
-In the last mission there are too many Worgen bases, gets kinda monotonous. Maybe change one of them with the Night Elves.
-In the bases the Forsaken get in the last chapter, after destroying worgen bases, might be cool if the Forsaken get heroes, e.g Nathanos and Koltira.