If this is covered in the videos I apologize but I have no sound on my computer, so Im just going off the text, and I don’t see this anywhere. Thanks!!
try straight arm pulldowns he demonstrates them in the third vid(i think) and mentions that its a good alternative to the Thib Lat pulldown.
2.standing barbell curls or DB curls just make sure you do the partials the same way
3.i think i remember thib mentioning he trains traps twive a week,once heavier with less volume and once lighter with more volume.rear delt work depends on your strentgh level.
hope that helped
cheers
edit:my bad i just watched the vids again he said anywhere in the 5-10 rep range is good for assistance work