Confused here!
You state that your friends didn't get a place at any of their 6 state school choices.
What happened was either your friends live in a catchment area "black hole" Where they are not near enough to any school to get a place based on distance (very unlikely indeed) or I'm afraid they cocked up the application either by listing only selective schools, which, however "above average" the child was they didn't score highly enough to get a place, or they didn't list their nearest non selective school as and "insurance offer".
If you place a non selective state school that you qualify for on distance criteria you will get a place. If your non selective choice is further away (because you didn't like the nearest) then you may not get a place as you have not met the distance requirement.
Summary- place the school you want your child to go to at 1. If this is selective and they do well enough, they get a place. If not the other choices are looked at in order to see if they meet the criteria set, either exam result or distance/religion etc.
PUT YOUR NEAREST NON SELECTIVE SCHOOL IN CHOICE 6 and you will be very unlucky not to at least get a place there.
Private school applications, bursaries etc have no impact on the state school applications.We've been through this x3 now (and for the last time thank goodness).
AS to whether being a "scholarship kid" makes any difference at the school- that depends on the school. Our youngest got a half fees bursary locally and we didn't accept but sent her via the grammar route. Mostly because the school was obviously less academic overall that the grammar, but also, whilst we could afford the fees etc, we wouldn't be living a horsey, jet set lifestyle, and she wouldn't be going on school ski trips etc as we wouldn't have the money. Maybe it doesn't matter at some schools, but I bet it does at others...