Some thought on your Points:
Music:
I think in most places Music is very fittign and cool, except for the example that you have given. So i agree when you are in any Combat Scenario the Music should Change to somewhat more engangin/thrilling. (but iguess this is not top priority atm)
Masteries(Sub-Classes):
I really enjoy meaningfull(permanent) decisions. So locking masteries should stay imo. It gives all your characters some sort of “thematic/feel”.
The only thing that i agree is that especialyl as a newer player you maybe need to test and mix skills to see whats good for you. So respeccing skills should be a little bit easier without losing all progress. But there are already plenty of discussions out there in the forums regarding this topic.
Auto-casting:
While i agree some some skills might feel tedious when you need to re-cast them every x seconds, while they don’t have any meaningful cooldown i don’t think auto-cast would be the best solutions.
As @ManiaCCC stated
While this would be an easy solutions for some skills it would take away one of your very few valuable skills slots and toggles/permanent buffs don’t feel very statisfying most of the time(except they do some gamechanging stuff to the rest of your kit)
My suggestiosn is that each and every tempoary skill/buff should have enough options in their skill tree for following things:
- Cooldown reduction(ALL tempoary skills should be BASELINE impactfull and meaningfull with some sort of cooldown, otherwise they don’t add much fun to the Gameplay i think)
- Increased Duration(together with cooldown reduction players could choose if they want a long lasting skill or a low cooldown skill and they could even combine that if they wish)
Auto-Loot:
I do not agree with autolooting ALL crafting mats. It feels more rewarding and controlled if you see what you looted, especially when you hunting after certain affix shards for your next big craft.
I could agree on auto-looting the generic shards like Guardian and Stability.
Boss Fights(and even some of the bigger elites):
Absolutly agree. And devs already stated that they intend to introduce more mechanically interesting fights, especially for multiplayer(for example mechanics that does nto just scale in X mroe damage or Y more health per player but maybe add additional mechanics for more Players.
Here is the post form a dev i was referign to, but feel free to read the whole thread, it’s really interesting.
Loot Filter: Well, the devs already confirmed loot filter for Phase 4, so it’s coming