Most to least situational:
Aquatic < Airborne << Venom
yes, a bit, but consider. Aquatic is unharmed by flooding, this should also synergize with shard of patience.
airborne is only good vs Wings.. but it is good with skyblitz, so you get a combo there
venom is indeed all around good.
these arent meant to be super great cards everyone will take, but rather simple cards that open new possibilities and strategies. as situational as each one is, they open many strategies. In this, I think they work. A few Quanta and a card to change the way a card works. Gills is about as useful as Purify, it only helps if they are doing something to hurt you, but can be used another way if you want. Airborne is not that great, until you add skyblitz. Suddenly your steam Machine is pretty powerful... or say a Lava Golem. Flying Scorpions anyone?