Depending on the cache difficulty I will go check after 3 or 4 DNFs. Yes by all means post a NM or shoot me an email. I want to keep my caches in good shape.
If people have filled one of my caches with business cards, coupons, small stones from the ground next to GZ & beer bottle caps I would appreciate your help.
We have some caches around here where the CO specifically asks not to post photos of the cache.
An alternative would be to take a photo of the cache container and e-mail that to the CO as proof you were there.
I always carry a Fisher Space Pen with a fine point refill...great for damp logs.
You wouldn't post the photo since as you say COs don't care for that. But you would email the CO the photo as proof you were there. Everyone forgets a pen now and again so no big deal. Most COs let that slide. Now if I noticed a cacher with a pattern of forgetting I'd think about some deletions w/o some other proof.
I keep a pencil and a fine point sharpie in my bag.
I have always gotten verbal permission from property owners. The only time I had to provide proof of permission was for an earthcache. There is some good informaton unnder Geocaching 101 on the main page if you want to create a letter.
Several parks deparments and tourism boards around ghe country have done this. Place decent caches, take me to cool places and the effort will be a winner.