I think the "hardcore" element of your post is misplaced. There really isn't anything that you posted (or in ESO for that matter) that is all that "hardcore" to begin with. About the only activities in ESO that might qualify for hardcore could be 12 man trials or maybe PvP. Completing all quests or getting high achievement points and the like is not "hardcore" IMO. Having a lot of playtime doesn't automatically make you hardcore..just a casual with a lot of playtime.

That being said I don't think you need to mention hardcore for your points to be valid. I agree with all that you said. This game needs more variety in activities and rewards. More activities to earn XP and more ways to get rewarded for those activities.

Why are there no rare or unique items or quests that would make repeating content worthwhile? Why are there no rare and powerful mobs with unusual loot tables that don't spawn in a predictable location/frequency? Wouldn't it be cool if powerful Daedroth bosses with unusual loot tables spawned randomly and wandered around in the vet zones? Why don't they create appearance slots for armor so that you could wear any level/type armor you want for appearance while still keeping the stats of your standard armor slots? That idea could be expanded out such that certain appearance armor sets could be found in various dungeons/delves/locations and would give a reason to go back to those areas to collect them even if you had leveled past that area and would be valuable to sell or trade with other players. Why don't treasure chests contain actual treasure that gets you excited instead of some pittance of gold and some crappy junk that nobody gives a second look?

I could keep posting more ideas but you get the idea. Most of these ideas are not new. It's been done before and works. No reason to not include what works in some fashion even if it gets an ESO touch but presently the activities and rewards in this game are very bland and don't encourage replayability for the most part.