I know it would seem dumb to have Anakin not turn to the darkside, which would end the story right there. Do you think he would have become more powerful with the light side rather than having turned to the darkside?
I think a Jedi Anakin with full training with all his limbs attached would become someone stronger than Yoda but not as wise. I dont think humans can live as long as yoda can. Against an evil Anakin with all limbs (not machine) would kick the sh*t out of Palpatine in a flash once he learns all Palpatines power. In an duel between the two anakins, I think the good side of the force would overcome.
The fate of the galaxy lies with the Empire.