Well I'll play. I'd like to be able to zoom in on your first pic but can't. It does look very simple to Rockchuck scat. They will live in and under old homesteads. Don't know where you took the pic, but, you wouldn't have any marmots over on the coast.
2. Feral cat
3. mink I would say from here. But, again don't know location of pic, possibally Marten, skunk.
4. weasel, both.
5. dirt eatin coyote.
Feathers. Anyones guess, I guess raptor picked a bird on that log.
Holes show no sign of anybody livin there. I'm sure a mink would poke his head in there when he goes by.
Big part of sign reading is knowing what speices inhabit the area and then a process of elimination til you decide on a likely suspect. Of course other evidence is important: In #1 are there any hairs stuck in those boards? If so what animal? Any seeds, insect, or scales in any of those scats? If so I'd change to a coon toilet.
Any tracks around any of them, etc.
When I was a kid I got a copy of petersons field guide to animal tracks by Olaus Murray. Great old book. I studied that book for years. In fact I opened it this fall to read what he had to say about wolf stride distance.
Soon you'll be able to tell the difference between coyote and cat tracks in the snow along the hiway at 60 mph!