We see Madara Susano'o has legs
Here's Sasuke & Itachi top half Susano'o
I think they will it seems kinda weird for them to have a top half Susano'o with no legs
You have no proof tobi told him anything, when he was a kid he acted on emotion and kill the men who killed his parents and for you to say if sasuke gets the rinnegan he wont know what to do with it is stupid.
Who taught nagato the rinnega when he was the only with it? When we saw Nagato fighting hanzo he didnt know about the gedo mazo didnt it come out of no where and him doing shinra tensei out of no where it seems his powered reacted on emotion.