I don't have any immediate answers for you, re: high-heeled shoes, but to answer your question - yes, SP3's rigging is horked (IIRC, V3's is somehwat off as well).  In fact, it's not just her legs/feet - if you check the 'center' of each joint, you'll find that her neck (? head? chest?) are not exactly at 0.0 on the X axis either.  It was a royal pain in the you-know-what when I was rigging the SP3 clothing (stockings and lingerie).

Daz is pretty sloppy about this with some figures, unfortunately.

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