Wow!  That looks great, Elleque!  I rarely use the fit function in the Fitting Room but just go with the work I did in the Pose room to manually fit the piece I want to use in the fitting room.  When I do use the fit function, I often have to fool with the poke through margin or I get a result like the one that you were troubled with.  Another thought about the issue with the weight map is that the content really did not need a Rfoot and Lfoot to work well and you might have stopped at Rshin and LShin and rendered and got a very acceptable result.

On the other hand, I think your result is wonderful! =)

Molly