I'll try to answer your questions,

1. Is there a shuttle between the IND terminal & ramp?
Yes. If you are jumpseating, call the ramp and they will send a bus to the terminal for you (in IND. In STL, you're out of luck.) Also, during the evening launch in IND, MANY crews are going back and forth to the airport Radisson & Holiday Inn (walkable from the terminal.) A lot of times, guys jump on one of these shuttles.

2. If you call the number will they tell you where to go?
Yes. If not, they can give you the local ramp number.

3. How many seats do the aircraft have?
The MD10 has usually been the scheduled aircraft between STL & IND, and it has 4 seats behind the cockpit door, and 3 in front. (6-7 total seats.) The A300 has 6 seats behind the door, and 2 in front. (8 total seats.) The STL-IND flights have always been empty. Almost every night. The only time I have seen a jumpseater on that flight is a CHQ/RP pilot going to/from work. So I guarantee you, there will be seats on that flight for you.

4. Crashpad info.
See above post, except as IND is NOT a FedEx crew base, there aren't any FedEx crashpads to be had.

Congrats!