Well, I’m not sure about the cave thing, but:
I had a dream or two similar to your first one after my grandaddy died. In the dream, I was following him around his house, when I realized that he wasn’t supposed to be there. I told him so, but I can’t remember his reaction.
If you believe in life after death (as do I), then yes, I guess it could be him visiting your dream to say good-bye.