I don't really think the main issue is with HP in-balance, although that could be a serious issue once the player-base settles and gradually falls off. For me the problems were within the game loop and combat.
I will admit I had a lot of fun exploring areas, but when I decided to stop exploring and fight enemies it instantly killed the fun for me, due to the long animations that don't weave into your characters momentum (playing Gunner). To me the NGS CBT reminded me of the Super Smash Bros series when Brawl came out where base PSO2 is Smash Bros Melee, in that, NGS lacks the complicated inputs that created pure momentum in combat. What's worse is that they took away a lot of PAs from the current selection of weapons in attempt to make them closer to scion classes, yet they don't really feel like scion classes at all, to me they feel like base classes with less PAs and longer animations, since for some classes many of the new PAs are just slower, flashier versions of the old ones.
I do think SEGA are aiming to gain a more casual audience with NGS, given the style of it and choice to take it open world. It's sad because it would have been 1000 times better if they focused more on making it a fighting game, which is where PSO2 was heading.
Lastly, it's important to remember that when PSO2 JP first released, the meta thing to do was farming MPAs, which felt largely the same as fighting boss enemies on the open field in NGS.
EDIT: My opinion has since changed on the CBT after the second day, I found the urgent quest combat to be very engaging with TMG / Rifle multi weapon (only using rifle weapon action). Then I realized the bulk of interesting content in PSO2 is urgent quests, or quest modes added later down the line, seems like the open map really might just be the exploration quest and story portion of the game, and the materials in the open world might drop in future urgent quests. I hope so anyway.