Played through Hexen on latest GZDoom with v7 and modified bosses, Mage, UV (Warlock in Hexen terms), no save scumming where possible, 1920x1080 with OpenGL rendering. No crosshair, though, gotta draw the line somewhere I guess. This rebalance is a godsend, I can't imagine going back to vanilla. With the (totally deserved) blanket praise out of the way, I have a few thoughts to share about my experience:
First, I played thoughtfully (i.e. less Doom-like), moving methodically and considering the "best" tool for each situation, but I rarely felt the Sapphire Wand was the right answer. The range limit is an excellent idea, please keep it because it promotes closer-quarters gameplay instead of tedious sniping, but maybe the afrit could be weak to the Wand instead of/as well as Frost Shards, to encourage some reason to pull it out. Then again, maybe not; maybe the Sapphire Wand is only a backup weapon now that Shards is a blast to use. Can't decide how I feel about it.
That brings me to the second thought, good Frost Shards. I am so into that. I gave so many icy high-fives this playthrough, it was epic. Truly the most versatile Mage weapon, and it feels so... so cool B-) but hypothetically, let's say Wraithverge's business end is in my back and I'll get ghosted until my ribs pop open if I don't find some nitpick. Fine: this playthrough, I had at least one Krater of Might at all times, with five of them in tow at the end of Necropolis. I never felt I had to compromise because of resources. I would meditate further on whether Frost Shards needs a mana reduction after all. I'll report further after I play Deathkings.
Arc of Death, I love you, and I love to hate you. It's so good except for when it sucks. That's part of its identity, which I've decided is practically perfect in every way.
Bloodscourge is a more compelling value proposition while still being expensive. Still costs more mana per kill, while dispersing groups faster, plus the ever-present possibility that it will mostly whiff if used irresponsibly. I am exactly on-board as you have it. Hypothetical ghosts would just be a fact for my ribcage, because I have no nitpick to save me from my rib-popping fate.
Centaurs... exquisite, they are so much more fun now.
The modified bosses are a welcome change to Hexen's lackluster boss offerings. However, the first Heresiarch did not get replaced properly because the HeresiarchNew and KoraxNew classes were defined more than once. This issue might only apply on the latest GZDoom. Script warnings popped up in the console. I switched the order that the wads load, which fixed the Heresiarch in Heresiarch's Seminary, but messed up the second Heresiarch and Korax. I would guess this happens because the Seminary Heresiarch might be spawned via ACS, but the Gibbet Heresiarch and Korax are probably pre-existing entities on their maps. Not sure what to recommend for fixing this.
Next up, Mage in Deathkings. Then Cleric all the way through. Then Fighter. Cheers!
This analysis does not match my experience with the mod. Overall I've felt it has been a huge improvement because it encourages each class to use more than one weapon, and it makes each weapon more satisfying and more effective at its particular job. The game is more fun when there are viable options other than "hit with axe, shoot with wand, spray with ghosts". This is especially true with the mage, who now almost always solves problems with frost shards, arc lighting, or bloodscourge better than vanilla wand ever could. I have finished single player runs using Cleric, Wizard, and Fighter on UV, UV -fast, and NM. I would not call any of the classes overpowered, nor are they too weak. I personally had a more difficult time with the Fighter than the other two classes, specifically with managing the Fighter's mana and flechettes on NM or -fast. It's hard to tell how much of that was because of my own preference for ranged options, but I thought it was worth mentioning if for no other reason than to reiterate that my experience with the mod couldn't be more different than the analysis above.