one way to make the skirt fit is to build a belt inside the skirt and fit the fabric to the belt. this ensures a sturdy and solid fit around your hips/booty.
try something like this:
http://sugarpetals.com/bra_belt.asp
scroll down to the belt forms. it can be strait across in the front and fitted to your booty in the back.
you can even make it out of denim or some heavy material. then make an opening slit in the skirt where the belt will hook.
after you embellish the skirt, line the belt area with felt. this will help protect all the stitching, absorb sweat and help give it "grip"
this is only one method. i am sure there are many other ways to do it.
as for the finger loops, hand stitching is the best way for those tiny little things.
hope this makes sense. good luck with the costume. when you are finished, will you post a picture of it? would love to see it.