Nice summary, but this looks like a writeup of somebody doing this the first time. There's lots of room for improvement.

First off, there's way too much planning going on beforehand. Having done several of these trips, my pre-planning now involves booking a single flight and letting things work themselves out from there. Dates on the calendar are really really bad to have, since they force you to move faster or slower than you want to. Avoid them at all costs.

And, of course, he overpacked. 90 liters is way too big. 40 liters is probably still too big, but at least realistic. You want to be able to fit your full pack on your lap on a crowded chicken bus without drawing angry looks from the locals. One complete change of clothes is plenty. Most of the stuff you think you need, you don't.

Beyond that, there's a lot of good stuff here. Sounds like he had a fun trip.