Solved! I'll post if something else happens.
I did a clean boot, started in safe mode on Windows 10, uninstalled my antivirus, and nothing seemed to work.
What did work was uninstalling all Morroblivion-related mods except for the core files themselves, so:
1. Unofficial Patch gone
2. OCO2 Morroblivion + Redguards gone.
34 Morrowind_ob - Expanded Quests.esp [Version 0.1]
36 Morroblivion - Better Clothes Patch.esp
37 Morrowind_ob - Nerevarine Armor.esp
38 Idol of Mephala.esp
57 2018-july-bloodmoon-fixes.esp [Version 2]
59 Ak- Morroblivion Maps HD.esp
I was then able to get load into the game with ENB working, 0.181, but my Bashed Patch was disabled, so I re-enabled Bashed Patch, but was still getting runtime error C++. Finally, I found out that was issue was Morroblivion Unofficial Patch. After having it last in my load order, and not part of the Bashed Patch anymore, it was still causing runtime error, and after deactivating it, with all other mods active, the game worked.
So for some reason, in short, the Unofficial Patch causes a visual C++ runtime error after about 5-6 hours of gameplay (not continuous) on my rig, regardless of if ENB is installed or not. This happens with the November 2017 version aswell.
I manually moved the voice files from Unofficial Morroblivion Patch into the correct folder, and they didn't seem to cause a crash, just as an fyi.
Edited by adrianoz, 03 August 2018 - 04:22 PM.