Hmm, How do i know if I am doing "real" dynamic skidded turns and not pivot turns/windshield wiper technique?
You shouldn't be pushing your back leg/tail around. If your tracks look like a washed out carve (S-shape), you are doing fine. The tail of your board should follow the turns reasonably smoothly and simply be traveling at a little larger radius than the tip.
If you are catching edges when turning, that should be a warning sign. Chances are, you are doing the windshield wiper technique or you are not tilting the board enough (which may actually be a big part of your edge hold issues).
If you are not too shy, just ask a few people that look friendly and look like they have a decent technique. Chances are, they will be happy to give you some feedback. Spotting the windshield-wiper guys isn't difficult...