Hi Dogz,I had the same problem with my Senior Telemaster.Turn left or right shoving the stick all the way over,she would take her sweet time turning in either direction.What I did was increase the aileron deflection.Or check the control rod that incerts into the ailerons for any loose play.If those rods are loose,flood the hole with gap filling CA or epoxy and let set over night.Is your LT 40 an ARF or kit?And also you could modifie the wing for duel aileron servos.

Your second question,my opinion for a good airobatic plane for a second plane would be a funfly type plane.Something like an Tower Hobbies Uproar 40 or a Sig Fazer.Hope this helps.