stone skin amulet protect you against ice ues as good as they protect you from sorcerers ue's.
Druids are nice, they are set up to have as much options as sorcerers, however there are things between them that make them not equal towards everything.
in some situations a druid is effective, but in other situations sorcerers is a better choice, the main question before choosing a vocation, is starting with asking yourself what you enjoy doing the most in the game, and chose vocation that fits the most for it.
If you are not good with low hp and die easy or if you lagg a lot or something, knight or paladin is the best choice because their health,
But if you enjoy living 5 hp away from death a few times/day, a mage is a better option.