You're probably not missing much on the creeks this time of the year. Most of the small coon are denned up. If you're interested in mink and muskrat you'll be missing them, youll pick up an odd mink in dryland pockets.
Even rocky creeks there's usually dirt somewhere farther up the bank you can dig into to make dry pocket sets or dirtholes. Just run a longer slider to reach water. Kinda hard to stablilize a foothold in the rocks anyways. For anchoring, I would probably wire off to big rocks. cabling to rocks is a bit riskier as it doesnt cinch up as good as wire can even when using a snare lock to hold the cable in place.
Carol Black's(Blackie) claim to fame was running a canoe line in somewhat similiar conditions, his interview by Clint Locklear is a good one and covers some of this:
https://www.youtube.com/watch?v=NlOBd9cAQ2s&list=PL5YP5pO2Puqoum8BmiF58NNnReQwnEm2F&index=5For the dp's, I will cable them more more times than not. I'm happier when I can use a drag. I dont worry about them being able to grab on to something. I try to avoid cabling to really bigger trees because they could possibly get the spring against the trunk and get some compression.
As for your feeders, I try to backset away from the feeder, at least be out of sight of it and blind set the trails leading to it (my pet peeve with guys running deer feeders and wanting me to trap coon there is the grass is mowed to nothing around them so trails cant develop)