Great report and pictures. I know exactly what lake you're talking about. It really is like quick mud! As you get near it, it's pretty firm ground, pretty firm, pretty firm, then WHOA you're sinking! Nasty stuff too. Smells horrible.
I wish I had a dune-able bike. I love quick, easy trips like these. All I have is my KTM690. Little heavy for the sand but great for adventures and desert.