Addressing few of the issues OP mentioned.
While I understand the lack of HP bars I sometimes want to have quick peek at the corner to see how everyone's faring. Like mentioned I can't really do much to them except for Healing Mist potions and stuff, but for example the area 5 sometimes has everyone doing whatever and wherever, it would be beneficial to get a quick view of who to go help. While I can see that on the screen as it is now, it would still be a nice option to enable the top left corner HP bars for those who want.
The 4 skill setting sometimes feels awful, but I understand there's a balance to that stuff. What I'd like to see though is the option to switch R1 (upper right trigger) and X button behaviors if so wanted. Often times for me the R1 button is harder to reach than X and door opening / looting (currently X) is often done in no hurry so R1 would perform there just as well. This is with PS controller. For PC and XBOX the things might be well already.
Heck, why not give an option to map all the keys as you like, for example all four skills to trigger buttons if you want. That shouldn't be too hard to enable.
Also what's wrong with the directional pad not working in menus? I feel it more natural for menu diving than the thumb pad thingie. In MP this is hardly an issue but in single player it would be a welcome addition since there's much more menu diving happening.