where i agree with you that public test realms would help to solve some problems that has be happen within the games but some of the system implemented in the game working as intended like the

ATMA system for you 3rd stage of the relic quest is good it make you work towards a better weapon by finding objects from the old era

The hunting system where that does need some improvements to stop the whole spamming of hunts and the insulting of people killing a B rank just cause they found before anyone else and not tell the whole server it there but that system is also working as intended it gave players a activity to do in the open world that give a reward for the discovery

Crafting mat that drop dungeon i dont mind this as it reduces the cost of crafted items on the AH as well as item that can sold for a reasonable amount gil but you also got to think that SE would need to make gear for each dungeon that would only get replaced very soon with SOl or ST gear

Where i can see PTR working in would be stuff like Dungeon and raids to make sure there balanced aswell as challenging to the player of different skill levels for casual aswell as hardcore player base