I think Booker was a far more serviceable PG starter than you credit him and that was with very little help around him . Find an average guard to play next to him and an average PF that can defend and space the court and we'll be in good shape until we can fill those roles with what we really want. I'd much rather it be a good point guard but I just don't see one on the horizon for us.
I think you're overrating Booker's raw assist numbers without looking at the rest of the picture. When called upon to play the point, Booker was a turnover machine, especially down the stretch of games where his poor decision making cost us at least a half dozen games. He also couldn't defend the point. Finally, he was so spent from playing out of position at the point that his play at his natural shooting guard position suffered in the not often enough instances he got to play his natural position, with his shooting efficiency and defense especially suffering.
As a point guard, Booker is below average, while at his natural shooting guard position he is a potential Hall of Famer. Force him to continue playing the point, and it hurts the Suns at two positions and hurts Booker as well.
Nobody in their right mind would have asked Reggie Miller or Brandon Roy to play the point. Booker, whose game is basically the same, shouldn't be any different.
We don't need a star point guard, but we do at least need a serviceable point guard (or at least combo guard who can play the point better than Booker) next to Booker, so, as another poster noted, Booker can be Booker.