plus like you said, if Leia has no desire she wont possibly become as powerful. All this taken into account why couldnt Yoda sense more potential in Luke?
as far as seperating them and how hard it would be to take them away from Padme at birth I agree, but that aspect was always present ever since Luke's comment to Leia on Endor, I think most people just overlooked it because we never saw the birth. I think Luke having a connection to his father and Leia having a connection to her mother works. but I still think that Padme should have lived for a period of time.
also, this is a stretch, but since it would be so hard to get Padme to give up both her kids they could have moved just one (let her keep the other, a compromise of sorts) in case Vader found Padme and Leia, Luke would still be safe (but really how safe would/could he be with his uncle if Vader knew about him and went looking? But Anakin also didnt know there were twins, so after he found one he might have stopped looking and the Jedi would still have Luke as an ace up their sleeve. Also, you keep saying that Vader thought Padme was dead, this is true, we know it, but remember its a movie, you see it from the outside...how do Yoda and Ben know that this is what Vader thinks. Also, from this aspect, for all they know Anakin is dead as well. But they dont know what the Emperor knows, and actually either do we, all we know is the Emperor lies to Vader and says that he killed Padme.
-Darth Simon