okay, so after reading a few more comments i've somewhat changed my mind about card errata. we probably don't need any errata for broken cards at the present time, just for cards that are worded badly or break rules as intended, or which are worded confusingly and need to be made more clear.
The game might be more fun and diverse with single purpose wands instead of mage wands/elemental wands, but i'm not sure that's actually necessary for game balance, so that idea's not a good one right now. We don't need to get rid of spellbind.
As for the druid being nigh unkillable without killing her tree, i suppose that one way to think of it is that the druid's tree is like a part of her mage abilities which doesn't become active until after the game starts and she spends mana and actions on it. if you think of the druid as a 34 life 10 channeling mage, and the tree as a 9 mana spawnpoint with 1 channeling and regen 2 and the ability to transfer damage to the controlling mage to make it more surivvable.... barkskin compensates for this, but barkskin has upkeep +2. so basically if your running a druid with a vine tree bonded thats' 34 life and 10 channeling on your mage, minus 10 starting mana and one quick action, and if opponent starts attacking tree and the tree needs to transfer damage to mage, barkskin is needed to compensate for that, which has upkeep 2 so thats like lowering druid down to 8 channeling effectively
So basically, the druid actually starts the game off at a mana and action disadvantage. She isn't overpowered, but maybe it would be a good idea to start attacking the tree sooner even if you don't expect to destroy it. the damage will be transferred to mage, then if she puts barkskin on it will be easier to gain a mana advantage on her until she removes it, which may give you more time to setup on her.