There's a lot of "room cleaning", but not more than in Baldur or NWN. The world is not randomised, the population feels like real characters needing real help on real issues instead of "kill 133 turtles in my garden" or "i've lost my amulet in that cave". Your skills are very varied, include telekinesis and lockpick. I don't think that many quests have different solutions, though, and there is no moral choices or moral systems I'm aware of. But it feels like a story and a real world exploration, while Diablo and Sacred felt like a shooter.

I don't like diablo-likes much, i like RPGs, and I adore Divine Divinity. I'd say it's worth a try. Despite of a slightly tedious beginning, where you run some errands in a village that misleadingly feels like the whole world at that point. Make sure to set it on high definition, too.

Ah, also, character customisation is not bound by your starting class, at all. I like that.

I think that was intentional, in regards to mages. They should just have communicated the fact that mages are best as support characters & not as main offense characters a bit better.
And what was wrong about the dodge mechanics?

I loved how much freedom the game gave you in regards to character design. While you had "classes", your class did not lock you into a single role, you could still diversify a lot. A mage could still become a good swordsman, and a warrior could still learn magic.

Apart from the ones that have been mentioned already ...

- Nox: an Action RPG but not random and more story-oriented than Diablo; after years and years I'm still struggling to motivate me enough to complete Diablo 2 - never had that problem with Nox. It also has significant replay value because as far as I remember different classes get to explore different areas of the game (available here on GOG.)

- Rage of Mages & Rage of Mages 2: Necromancer: A blend of RPG and RTS, but the only one that ever worked for me - I actually kind of dislike RTS, but I enjoyed this series. There are no building phases or the like, it's just that the maps and the combat are similar to RTS games. (Currently not available as digital download though, AFAIK.)

- Revenant: Another story-oriented Action RPG without the random parts, although admittedly it has less story than Nox and Divine Divinity and is quite linear. Probably not your first choice, but I liked it anyway. (Currently not available as digital download though, AFAIK.)

- Lionheart - Legacy of the Crusader: I haven't played it myself yet but it sounds comparable to Divine Divinity in that it is a story-oriented Action RPG with roleplay elements that is said to be interesting during the first half and gets more and more hack-and-slashy and boring towards the ending (available here on GOG.)

- Silver: another linear Action RPG with a JRPG touch but real-time combat; a fun game, but I'm not sure it's what you're looking for (available here on GOG). (Not sure if this counts as isometric, but as far as I remember at least the backgrounds are static like in BG.)

All others I can think of are turn-based (Avadon, Geneforge, Avernum, Albion, The Temple of Elemental Evil ...) or 3D - although technically Neverwinter Nights is not isometric either, so you might still be interested in NWN2 (available from other digital distributors with DRM) or Vampire The Masquerade Redemption (available her on GOG).

I am surprised nobody has mentioned "The Witcher". While a little more action oriented it uses a derivative of the Aurora Engine from NWN.

Probably because it's just as much isometric as NWN - that is, not one bit. ;)

But if the OP liked NWN, The Witcher is definitely an option.

Yup you are correct on that one, I merely bring it up as he listed NWN in his list of likes!

I would also suggest :

-Darklands. On GoG.
-Ultima 7. On GoG as well.
-Dark Sun : Shattered Lands? Morelike topdown than isometric though.

My other suggestions would be to mod the games you really like. 1.13 for JA2, Sword Coast Stratagems I and II for the BG series, CO8 for TOEE...

I find these mods completely necessary to play these games. They give the games more life to them, and it's almost like playing a new game really.

Or ... play one of the myriads of great community modules for Neverwinter Nights (in case you just played the official campaigns and premium modules, you're really missing out on what this game is about). ;)