Not a bad idea. However, for me the bagging/tagging was not as religious on some items, as on others. Some things are no-brainers. Others...not so. The clips and such that are part and parcel for the items attached to the rails, like fuel and brake lines as well as e-brake pieces are harder to keep up with, if you can find where they go when they pop off. Luckily, they're available from places like
www.inlinetube.com.
The shims that are part of the upper control arms....the pieces that are between the rail and the upper control arm...are what aligns that part. I labeled mine for the front or rear/ left or right. The studs stay on the rails.
The placement of the crossmember for the transmission is good info, but I figure that installing the engine/transmission assy will dictate where the crossmember needs to be. With the cab off....shouldn't be too hard.
No checklist is going to it all and make reassembly a walk in the park. The experience of dissassembly will do it for you.
Have fun!