oh wize jedi master the challange you present.....
double hauling is a must, even to get 70' forward. I guess the only way that you could pull that off is if you turned your back cast into your forward cast, but then it wouldnt really be a back cast now would it?
As far as a 65' roll cast I dont think thats much of a challange, if you were to use a 15' two handed 6 wt. spey, and a fast sinking line, with the wind assisting. (this rod would have to be made along with that 10' 1wt. noodle that you were talking about)
And lets not forget the backward curve cast, I do that all the time, by twisting my wrist and not watching my back cast. (of course I use a 9 wt.)
But if I remember the above mentioned challenges were for a 9' 6wt.