1. Check the flight status early. If you choose to take the 0800 through flight, it is likely you will have paid the $4.50 extra, and end up with fewer miles.
2. 90 minutes should be OK.
3. Probably the RCC at C18.
4. They start boarding 45 minutes prior to departure. You should probably go with that.
5. I personally absolutely do not like the bulkhead, period. I will always get the isle seat, exit row, while travelling in coach.
6. Never been to KIX, yet.
7. I can't think of anything else, in coach that is.