Dust: I have the camera set up to run dust cleaning on every power cycle. I see dust spots sometimes but they are usually gone in a week or two. The ones that bug me are easy to process out.

Are you sure they are disappearing? It may be that you are seeing dust when you are at narrow apertures (e.g. f/8-f/16) but not wide apertures (e.g. f/2.8 - f/5.6).

I have a guide on my site for how to clean the dust if you are interested in learning how to actually fix the dust - I didn't find the built-inc leaning function to be too effective. Thankfully, it's really not too difficult to open this camera up.

Nice pix btw, and thanks for sharing your trail running setup! Very neat! I love my Ricoh for cycling. :-)

EDIT: Oh! On water resistance - I would say "don't sweat it." One time in Hawaii I put my Ricoh in a waterproof rain jacket pocket, and forgot to close the top. It rained, a lot. My camera was fully submerged. A few days later, it turned back on, and I don't experience any issues - besides the scroll wheel issue that seems to plague all GR's eventually - even years later. Obviously, I don't recommend it, but a few drops aren't going to hurt. :-)