For me a boat with weather helm turns really well in 1 direction-upwind.
what do you mean by the boat won't turn?
weatherhelm makes a boat hard to keep going in a straight line. also it's tough to bear off and jibe turn with excessive weather helm.

toe-in and sailing w/ 1 rudder up is mostly dealing with play in the rudder system and the boat platform itself.
turn your metal hooks clockwise untill the rudders are forward enough to keep the boat sailing slowly up into the wind when you let go of the tiller instead of rounding up hard.