The goal in combined knitting is NOT to end up with a twisted knit stitch, quite the opposite, just as in english or continental knitting. So you drop sts to fix mistakes exactly the same. When you knit in the round combined, you do it the same as you would continental, there's no need to change that. However you knit or wrap the purls, just work into the leg closest to the needle tip and that will result in untwisted sts. The knit and purl videos here include combined, and I'm sure you can find some on you tube as well.
Fisherman's or brioche is tricky, have you looked at www.briochestitch.com
for how to fix mistakes? I can't drop sts in it, but I usually spot the mistake on the next row or two so I just take it out. I've been able to rip back and reinsert my needle to fix the sts that are out of whack.