First of all yes. If using a skirt you are likely to get a pantyshot. No, I am not sure if it will work on males due to me including a dubious tag.
Seems stable enough but It has only received limited testing. I notice that in some wider images it might do a third leg, but the model itself did so too, so YMMV.
I tested mostly on standing, sitting and on_back. I saw it work on legs_up but in a more limited range. Haven't tested on split_legs or other more esoteric poses.
The extremes are crossed legs and spread_legs with some supporting concepts. Seem to starts acting Iffy above +-2.5 so that's on you and it might depend on the model.
It does require the legs tags to use and you can use the common tags like spread_legs or legs_apart plus the leco for even finer control.
LECOs are manipulated by their weight and normally need no triggers to use it(this one does), change their weight like this <lora:SpreadLegs:-1> to make legs close or crossed <lora:SpreadLegs:1> to make the legs more spread. Remember you can go further than -1 or 1!