Still chewing over all this. I’ve got a week stuck in a classroom away from the machine, being taught things I already know, so naturally I’m thinking about it a lot. And I’ve been trawling other people’s build threads and have a few preliminary conclusions that might be of note:
- Clone routers without electronic speed control seem to cause major problems, not least since they probably have a RPM floor that’s way too high. This was part of my woes, this builder also had issues. See also: 80mm Spindle on LR4? - #65 by Rico_LRS I almost want to suggest adding a warning to the docs, but I think others have been running these clone routers with no issues?
- Really cheap bits also seem to cause major issues, again, same builder linked above had similar problems to me.
Can’t seem to draw any other significant commonalities of issues from my comparison spreadsheet, but I’m still adding data as I find it.
Guess I should try some better bits, but I’m hesitant to do so as I think the problem with my particular machine is more than that (almost at the point where I can quantify my “worst LR4” comment 
), and I’ll likely just ruin them. Still looking for advice on all the other questions, as well, any thoughts would be really appreciated 
Otherwise I’ll just keep talking to myself 