Haha, I'll have to borrow one of these rubber mentors from my kids next time I'm stuck
I was thinking about the misplaced parts and one strange thing that that baffle my mind why (some) of the parts (or their dejavu copies) are placed in such an odd angle. I then remembered, that my assembly was aligned wit GCS until some very late stage of assembling, when it got somehow misplaced. I think I tried to hide and show some parts around that time.
Just a thought, I'm not sure if it's important.
I still experience extremely long times when using Move tool, I guess it recalculates all assembly solution after any move/rotation even when auto recalc is off (is it?). With such assemblies, you can nearly go have a tea (even with Hi-spec PC) even with simple move of one un-constrained (!) part. As reported months ago, it's same on W7, W10 and OpenSuSE Linux. If above assumption is correct, it would be great if (yet) unconstrained parts can be removed from recalculate trigger and if it was sensitive to setting of auto-recompile button.
The hiding was a result of those desperate low speeds, but it didn't help anyway.
Sorry for not being more specific then this, console doesn't show anything interesting, so it's just what I see.