I think your start time would be about 9:45. I am a 1:40ish and have started at about 9:45, I dont think there is any problem with you starting later, earlier might be a problem when the speed machines are out.
You could mail Irondog, I believe he is one of the organisers.
If you look at Irondogs post, the first one on this thread that is a pic of the tunnel. Handrail if you need it, bit slippy underfoot but as long as you remember to take your sunglassess off you will be fine
Although totally flat its not really a PB course, the course depends upon weather but I will go for a pair of old road shoes, they will get muddy, not racing flats. MT shoes will be fine but not really nessacery. Most good gravel.
The bridges towards the end of the race are the killers, just 10' high each but enough to begin to hit already tired legs.
I will say this is a great race, my 5th running. You will love it or hate it though.