I don't play with Ballista. I can see it being good for the Druid, but I expect it to be fantastic for pretty much any build. Particularly the Forcemaster.
The issue I've found with playing Vine Tree and Battleforge on turn 1 is that it leaves you in a poor position to adapt to a Lord of Fire rush. Galador and Tarok can help, but you've invested so much mana in action advantage that doesn't help you play them that it's difficult to efficiently respond. You can prevent the Lord of Fire from killing you quickly with Dragonscale Hauberk, Elemental Cloak, Barkskin, and Lifebond, but it's very difficult to keep your Vine Tree alive, and playing plant creatures from your Vine Tree just seems like throwing more mana away. Lord of Fire just kills plants so quickly.
Other sources of fire damage aren't nearly as big of a problem. Lash of Hellfire can be destroyed with Dissolve and Corrosive Orchid pretty easily, Circle of Fire can be Dispelled, and Firebrand Imp and Flaming Hellion are weak enough that you can focus them down. Attack spells are one shot, so you mostly need to worry about eating a zone attack.
I think I'll try running a build with just Vine Tree for action advantage, and more Acid Balls and Burst of Thorns. Acid Ball and Burst of Thorns allow you to more efficiently focus down and armored targets like Lord of Fire. It will also be easier to take advantage of my animal support.
