Steve-
1) Place to stay-As you pass through the northern traffic loop, you head up a rise. At the top you'll see a left turn lane to N. Long Jim Loop. Turn left and you are now in US Forest land. Follow the dirt road and it will drop down the ridge into a low land. The map shows the left turn, and when it turns left to the south, you're at the spot mentioned above. Great sites on both sides of the road- no car traffic noise or town lights.No need to sleep on the ground- a cot will make it comfortable. I have one if wanted.
2) The staff at the entrance station can help you get your own Senior Pass. Just show your Drivers License and $10.- as you know.
3)I'm thinking that the side road south of the train tracks would be a great place to pick you up, and for Julius to find his car; once his walk is done. That way he can hit the ice crean store, go check in, and then get the car/luggage. The building is the old power station, and directly across from the Bright Angel Lodge and stairway.
4) I'm working Thursday, so I can give you a lift to the trail head, but won't be able to take a morning walk with you. We can set a time for me to pick you up, etc. in the upcoming weeks.