One question: Is it plausible that Thomas Wayne Jr. and Bruce Wayne would smell EXACTLY the same? I mean, they're brothers (both from the same family, just alternate earths) sure, but do they both use the same body wash?

Thomas wouldn't smell the same as bruce, I'd hope. I mean, similar costumes, to a point, similar training, almost... (I like to think of Owlman as better, because he isn't afraid to kill if the situation calls for it.),