Mt Fuji - accommodation and transport

Hello,

I am planning to climb Mount Fuji in the peak season (early August). May I ask some help with the following problems:

1. I would like to stay overnight in one of the mountain huts. How early I have to book the mountain hut? What would be the earliest and the latest time for such a reservation?

2. Before the ascent I consider visiting Sengen Taisha and then getting on the bus from Fujinomiya Station to Fujinomiya 5th Station. However I am afraid whether I will really be able to board the bus, because I expect it to be very crowded and possibly already fully occupied since I will not travel from the beginning of the route which is Shin-Fuji Station. Should I really worry about it?

[3] After sunrise on the summit I would like to go back to Tokyo in the fastest way. What would be the best? If I start the descend early, is it possible to be on time at Fuji Subaru Line 5th Station at 8:00 or 8:30 to board the bus to Fujisan Station and then continue the travel by Fujikyu Railway? Alternatively, if I board the earliest direct bus from Fuji Subaru Line 5th Station to Shinjuku (departure 10:00 am, arrival 12:25 pm) may I really expect that bus will reach Shinjuku at 12:25 or is likely to be later because of traffic jams?

Hut reservation begins in late May or early June which depends on the hut schedule.
If you climb in the early August, an early booking is recommended because the climbing season at the time is very busy.

Not sure about the crowdedness in buses.
If you can catch one of buses which depart Fujinomiya sta at 9:05, 9:55, 10:55, 11:55, 12:55, and 13:55, between July 11th and August 31st, these buses stop at "Wakutama-no-ike" bus stop for 15 mins, then you can visit "Sengen taisha shrine" which is 3 mins walking distance before you depart for Fujinomiya 5th station.
This service is only available on the above schedule operated by Fujikyu bus service.
http://goo.gl/D1Sofw

The bus fare between Fujinomiya sta and fuji 5th sta costs you 2030 Yen for single, 3100 Yen for return but you can only purchase the return ticket at Fujinomiy sta.

The fastest way to Tokyo is Fujinomiya 5th station bus stop to JR Mishima sta which takes approx 120 mins and then catch a Shinkansen to Tokyo sta which takes 44 - 57 mins between Mishima and Tokyo.
or, Fuji 5th sta bus stop to Shinjuku sta by highway bus takes approx 150 mins.
The chance of you can see the sunrise in Mt fuji is 50%, and reach the summit is 70% because of health and weather conditions.

And also, before you leave for Fujinomiya 5th sta, take a toilet rest at Fujinomiya sta or wakutama-no-ike bus stop. There is no toiletry service after that nor no toilet on the bus. The bus driver always announces that on the bus. It takes 100 mins between Fujinomiya sta and Fujinomiya 5th sta.