Dog/Yote. I believe Black Bear has 5 toes on each foot. I remember the claw marks not being associated with the to impression (as in the claw touches beyond the end of the toe). I am not 100%, it has been almost 10 years since I last saw black bear tracks (confirmed).
All of those tracks are canine. I would go with dogs, because the outer toes point outwards, not forwards like a coyote. Coyotes also usually double register (one foot in the same track) and those do not.
The tree looks like a dead tree that was dug into by woodpeckers, raccoons, possums, etc., looking for bugs. A bear would have pushed that over by now.
Nope, nope and nope. What you have there is some dog activity. As far as the tree, I'm not sure, but I would guess maybe lightning, unless someone's been using it for target practice.