I only know about #2, the shivers. Yes, this is common. I get shivers in all different parts of my body, not during meditation, but at all times, for no apparent reason. Some people think it is kundalini energy. i don't know. What I like to do is avoid letting it cause my body to shiver. I put all my attention on it and instead of physical shivering it turns into a wonderful feeling inside.
I can't tell you what I'm doing even, but I like it, and yes, the shivering is common.