Radiant Barrier installation questions?

Hello All,
I started stapling some radiant barrier to the bottom of my rafters and would like some input please. We have a hip roof with two electric ventilators, btw.

1) It's my understanding that I am to begin stapling the first run of radiant barrier near the bottom of the rafters but not all the way down. I am supposed to leave an opening at the very bottom of the rafters so the cooler air from the soffits can enter.

So does this mean the opening just needs to be available for the outside wall/soffits -or- does the opening need to also be open to the attic space? In other words, the first run of radiant barrier must remain above my blown-in insulation and open to the attic space.

2) How much of an opening am I supposed to allow at the bottom and top of the rafters for the air to flow? Do I allow 8in, 10in or 12in?

3) Lastly. Because we have a hip roof most of my rafter lengths will vary. The jack rafters begin on the outside wall but they end at varying lengths on the hip rafter which of course goes all the way to the top ridge. Please confirm the obvious, I am supposed to cut holes at the top of all of these rafters so the hot air can then exit to the very top of the attic?

Thanks,
Ralph