You need a better set of tires! That DRZ can handle the muddy areas much better partially because of the knobby tires. Get yourself a set of DOT knobbies and the trails will be easier for you with probably fewer crashes. The trails your photos show looks like fun, though. You've done good being able to successfully navigate them.
BTW, spraying the under sides of the fenders and other areas where mud tends to collect with Pam cooking spray or something similar just before you head out will help cleanup a bunch when you get back. Keep a close eye on brake pad wear, particularly in the rear when you're riding in muddy conditions. The grit will eat up pads.