Probably about 4:30 to 5:00, but that will depend on a red or blue start..not sure if they start next to each other or in different areas. If different areas--one area will of course be farther away from you.
Head out the drive in entrance of OKW--safely cross teh street and then the median and then you are on the road that the start is on.
I am not sure what you mean by the wrong shoes though. If you have not had any trouble thus far.....it is better to keep them unless they are totally in need of replacing (they have damage or you have had increased foot pain due to the total milage on the shoe).
Typically you replace a shoe between 300-500 miles. Typically you want your race day shoe to have about 100 miles (meaning you wear them for 100 miles of training prior to racing in them).
It is going to be very hot--make sure to stay well hydrated. That will be the biggest shocker. Bring running clothes (That you have worn) for warm weather...which for most will be shorts and a singlet or short sleeve shirt.
Comfort in the heat will be more important than if you hadn't run in a particular outfit before due to the climate you are visiting from.
Make sure to bring some body guard to place in all areas where chafing may potentially occur---around the sleeve edges, on the chest area (I chafe at high mileage in my chest area and it HURTS!!!), around the thighs, etc.