it’s a pointless waste of time having to start a brand new character just because you want to experiment with everything the game has to offer.
But how else can they get you to spend more time in-game and increase the chance that you might just wander on over to the MTX shop and give them money? /s
I've been enjoying the game, but I'm already starting to feel like some of these time consuming processes have been put in just for this reason. Why would you buy horse armor if you're not riding around all that much?
The easiest way to figure out which ones you are missing would be to use one of the interactive maps where you can check off the ones you already have. (I can link the map I've used, but don't want to unless you want it.) As far as I know the only waypoints that are locked by quests are the ones attached to strongholds.