2. If your bike has a threadless headset, buy a Problem Solvers Locking Headset Spacer. You have to remove the bars and stem to pack the bike and, without the locking spacer, the fork will want to fall out too. The spacer retains the fork and keeps your correct headset preload adjustment.
4. Park sells a small light pedal wrench (RW-1) that is a great take-along. Otherwise a 15 mm cone wrench is also usable. Pedals don't have to be that tight.
Couple of comments - I've traveled with our tandem on Amtrak several times. On Amtrak it is only necessary to remove the bars. I turn my 10 degree up threadless stem over so it fits in the box better. No retainer needed and it makes is easier to maneuver the bike into the box. No reason too that you couldn't spin it around and lash to the top tube. Now that Amtrak no longer takes tandems my investment in S&S couplers is paying for itself. Be sure you have the little clicking torque tool for the bars.
The S&S wrench includes a 15mm slot for pedals (in case you were wondering what that slot was for) . . no extra wrench necessary unless you have pedals that don't have a wrench face (some Shimano SPDs are like this). If you put the pedals on with this wrench, you will most likely be able to get them off.
Santa Rosa CA