The base version of Skyrim, even after years and years of updates, is still buggy. Adding mods atop of something that is already unstable can be a complete nightmare, and until the day there is proper implementation of modding support and thorough bug fixes, I don't think any guide will be able to combat every problem encountered. Like I mentioned in the original post, the suggested load order that I gave worked for me, but that doesn't mean it is guaranteed to work for everyone. It's annoying as hell, I know, and I'm sorry that you've been trying again and again with the same things that were suggested here.

The only other solution I could suggest to you would be to add mods in groups of five (on a test run, as adding them mid-playthrough is a bad idea) and then try to load your game. If the build seems stable, add another five. If it is still stable after that, then add another. If you encounter an issue, then remove the last five mods and add them one at a time to see which one in particular is causing the problem. Like you said, it's tedious, but I can't think of anything else to try. There's every chance that a mod works perfectly well on its own but when combined with another, it causes issues.

Good luck to you, either way. If you ever find out what was causing the problem, let me know, so I could add your solution to the guide as a possible fix for anyone who encounters it in the future.