he would have wanted to kill madara next remember when he fought itachi he asked whol helped him and he said he was going to kill him to or sumthing like that
so he def would have went after madara and i dont think he would have gone back to the leaf until he was finished
He could also stay as a missing nin, I mean going back to the hidden leaf where the Uchiha's were slaughtered is like a devils playground. Sasuke has no bizness going back, well thats what i think
he wouldnt have gone back to konoha. probably try to kill tobi and get killed himself. tobi even threatened to kill all of taka if they betrayed akatsuki.