Can't find this info for the life of me, and I need to know in order to optimize my point distribution.

mmm dont think there is a max level, you won't reach very high levels, but i dont think there is a set top level you can reach. 40+ keep on going baby ...

Some things.. few posts below "game mechanics" i did a long time ago might help with some stuff, has the link to the official strategy guide also which will give you the max spell levels for characters and skills.


https://archive.org/details/Throne_of_Darkness_Prima_Official_eGuide

I don't know the max level cap, you can head to YouTube, where user Grasyl has made a lot of videos about this game (he's German so his English is a little awkward at times, but nothing major).

Here is a trick I picked up from one of his videos I found while looking if the game allowed farming :
There is a limit of sorts in single player because the amount of monsters and loot is finite, but since you can use your SP clans in MP you can farm ad nauseam, as long as you don't activate the portals in the Slope Cave, the Dark Warlord's Outer Citadel and the Dark Warlord's Shrine Room.

I mention this because, (as he says in the comments of the video I linked), in v1.12.18 (stable GOG version), doing so will corrupt your SP save, making it unuseable (you can always make a backup).
However, it seems updating the game to 1.3.2(Beta)* will fix this bug, however you'll have to update the game manually.

Exploiting MP with your solo heroes is very beneficial because while SP uses full snapshot (player + environment) saves like Diablo 1, MP only makes player-snapshots (like Diablo 2) and each MP new game will reset everything, allowing you infinite farm for gold, gems, weapons, items and armor, thus allowing you to do some much convenient crafting and disassembly with your blacksmith, and giving you plenty of money to also barter with the monk.

Also, you'll be able to overpower the difficulty of the SP game and correct any mistake in spec'ing your characters by compensating.

*1.3.2 is a fan-made patch that adds difficulty selection and fixes bugs and glitches.
You can download it here for instance.
They also talk about it here on GOG, it demands some fiddling, so YMMV.