Seems it will be F2P after all! This thread never went very far ages ago!
Dont worry, it wont be F2P. Originally the plan from the devs was to make it F2P, but there was a poll (after the interview in the OP took place), where an overwhelming majority of the players wanted the game to be a standard retail game, so the devs have changed it to a retail game.
The aim was for the physics to be as good as if not better than iRacing, Assetto Corsa and the like. I can't really comment on the state of the physics though because I haven't played project cars in about 5 months because of uni work. From previous experience I know that the physics will have changed dramatically in that time.
As a slight aside, if you have seen the E3 gameplay video then don't make too much of it physics wise. For some reason there was a bug with the in car camera that made things look all jerky and generally look odd. (If there is more than one E3 gameplay video then you'll know if it has the bug or not)
Ps. If this thread doesn't pick up in activity, you could always pop into the PC games thread.