On the bone wall issue, it doesn't feel too imbalanced to me, but that could be because I expect to swarm sooner or later. Bone wall is weak to the number of creatures, not the quantity of damage anyway... if you're relying on, say, 5 heavily boosted creatures then essentially your deck is weak against a bone-wall. On the other hand, if you play a bone wall deck, then your deck is very weak indeed to a swarm deck - 24 fireflies eat through that wall like no tomorrow.
Finding a hole in your deck isn't a reason to cry imbalance, but it is a reason to try and tune your deck to take account of weaknesses you've discovered in it. Add a boneyard or two and a rain of fire, or some plague abilities, and you'll soon eliminate your enemies' creatures, and the subsequent influx of skeletons will batter any increase in their wall like crazy. Or add a steal, steal one bone wall, and then destroy all their creatures (plague or whatnot)... you'll be nearly as well protected as your opponent is.
That said, one thing I do find silly is the way the AI continually does try and deflagrate and steal bone walls if you have them, when it often has much better targets to choose from given bone wall's difficulty to destroy with spells.
Of course, as and when a card of the flavour "return target, and cards initially identical to target to their owners' decks" comes into existence, if bone wall is immune to THAT, *then* I'll be surprised. That would be incorrect.
