Firstly i don’t play this long and i love this game, for someone who played hearthstone… this is like 10 times better so good job on making it.
As for the balance issue, this is the main problem which is quite specific but can just ruin a game on the 2nd turn, when your opponent (or you w/e) plays second, first turn he 3 neutrals down middle, second turn with the 8 faeria he drops a mountain 2 lands from your orb and drops a Kobold Warlord on it and thats 3 turn leatheal (2 if he has gift of steel) which you can not do much about it except trying to block it with minions which just gives it 3 attack and its still 3 turn lethal and you wasted faeria on doing noting but some dmg to it. There very few answers to this start, like Verduran Force or some Deathtouch minions which you will usually not have nor keep in your starting hand and even those answers can be dealt with gifts of steel kill Force and red has cheap removal for Deathtouch minions. Even if you do kill it by blocking with minions you’re so far behind by that stage by doing nothing but suicide minions for 2/3 turns that it doesn’t really matter you killed it.
That kind of game is not very fun to play.
So basically what i suggest is make the Kobold Warlord #2 Red Mountain# requirement instead of 1, which does not sound like a serious nerf to me and it would delay this, what i consider broken strategy by 1 turn which i believe would be enough.