I still have some open:

6'    "Talk about your plenty, talk about your ills,
       One man gathers what another man spills."

               hint 1: likely known mostly by their faithful fans    hint 2: group played 3500+ live concerts

8'   "It's what you look like
       and not what you are"

9'    "These are just some sorry kids
       ... they ain't the ones"

10'   "You would stand to gain and I to lose"

11'   "She's a gal with a portable past"

12'   "I think we'd be better off
         ta just run her off this place"

These can't really be that hard. Some of the artists are Jackson Browne, Robert Earl Keen, Jethro Tull and The Grateful Dead!