JR pass for Mt. Fuji + busy dates

hi,
i plan to go Kawaguchiko by bus,
and to valid my 7 days jrpass there, is it possible?
if not then where close place to do that,

and if yes, i want to go from Kawaguchiko to kyoto.
is it possible or its better to take a bus back to kyoto and then take the fast train to kyoto.

and one more thing,
i plan to be on kyoto between the 12 july till 18 july (have to back to tokyo on the 18)
i know that i can change my jrpass for reseved tickets only when i valid my pass
and im worry that i will not have a seat on the 18 of july beacuse there is holiday and this is a day after the gion festival on kyoto,
is there any chance that i will not have a seat if i try to have on the 12 of july when i valid it?

thanks a lot and sorry about the mistake on my english:)

ohad

There is no JR station at Kawaguchiko.

You need to rethink your plan as is will not work as intended.