I'm not sure about any of the places you listed, except that I agree that you're probably too low for the Permafrost bears. At times like this I always love to refer to the Per-Level Hunting Guide, but in this case it doesn't have much in the way of Druid-specific places for your level:
https://wiki.project1999.com/Per-Lev...ng_Spots_50-54.
It has the already-mentioned raptors and burning woods giants. If you don't care about faction you might be able to quad Barbarians or Wood Elves (a friend of mine killed the Barbarians on live with his Druid pre-Velious, but I'm not sure if he quad kited them). You also might be able to animal charm the sonic bats in Sol B, or the sharks in Kedge Keep. You
could also start doing the named cycles in Skyfire, but you'll probably be too low to kill any of the good stuff (and I'm not sure if you could quad the lower-level ones because they include casters). Once you get a few more levels though that cycle was sort of made for Druids.
Everything else probably is a non-Druid-specific root/rot spot ... which is obviously less ideal. But my druid is only 39, and thus my knowledge is limited; hopefully some level 60's will have more ideas.