Despite what the LR instructions say, it is not a two person job. That being said, I did put some foam board on window while fitting ladder, as well as painters tape above and below trim piece.

Trim piece holes: I watched the PowerfulUK video beforehand. One of his pointers is to drill the hole in the trim piece slightly above center. I did this, but it turns out it should be WAY higher, partly due to the bolt coming in at an angle. I drilled the hole using a 3/4" spade bit (closed thing I have to 19mm), but I ended up having to grind the top of the hole pretty much just into the top shoulder of the trim piece.

Roof rail mounting: despite what some have said here, you do not necessarily need to mount the racks or ladder first- it depends on which roof rails you have. If you have one with several large slots at both ends, then it doesn't seem to matter. If you have one with fewer slots then I think the order would matter.

Torques: the translation for the torques are ~ 35 ft-lbf for the side mounting, ~53 in-lbf for the top mounting.

Top mounting: per Simon at PowerfulUK's advice, I used longer M6-1.0 bolts to temporarily holt the ladder in place until the short little bolts in the kit could be fitted. Makes it much easier.

Top mounting alignment: The LR instructions say to align so the bolts are centered in the holes top to bottom. My ladder frame may have been subtly warped, as it was a real bear to do this- when one was lined up, the other wasn't. Finally got it lined up by putting a drift punch in one of the elongated holes to prevent it moving and manhandling the ladder to align the other. I ended up going a little above the advised torque in hopes that will prevent movement. In the end though, The alignment really only affects the spacing from the window. Not sure it would have been noticeable if it wasn't perfect.
.