Not a large sample, but I've just done 10 games vs AI3, with 3 losses (vs aether and light/wind. Did not face time/life ~ don;t see it turning out well) and 3 wins with fewer than 20hp remaining (but this happens regularly with my steal deck anyway), using your Steam Machine deck. Replacing freeze with ice bolts would have helped a bit, though. SM seemed vulnerable.
These are very interesting results. I played a few games myself, beating the decks you lost against with well over 50 hp. Let's examine your claims that ice bolt is better than freeze and SM is vulnerable:
aether:
I concede that ice bolt are better than freeze against the phase spiders. However, phase spiders do not make up a large portion of the deck's damage potential. As for PU'd Steam Machines, freeze is better (although the inclusion of steam machine causes this advantage, I admit).
steam machine survives at least 1 hit of all CC. The only problem is the PUs, which will target Steam Machine if its attack is greater than phoenixes.
Also note that RoF can 1hko phoenixes/phase spiders, and the extra ice shield makes it very hard for this AI to kill you before you can draw at least one Deflagration, and that you can easily kill the AI by dealing damage equal to the rest of its HP in that turn of vulnerability.
light/wind:
Crusaders have 4 HP, so you need to either be lucky to get 10+
or purposefully build your deck to generate excessive amounts of water. If the Crusaders get to endow, then you need 20+ water. Note that freeze stops crusaders from endowing.
Wyrms have 3 HP, which means that they can't be killed by Ice Bolt but can easily be killed by Rain of Fire.
Pegasus can be killed by both Ice Bolt and Rain of Fire.
Flying Owl's Eyes can be frozen, but are extremely resilient to death by Ice Bolt.
Steam Machine takes 2 turns (4 after it's played) to be killed by Owl's Eye, and can survive at least one Shockwave.
Again, note that this AI does not have permanent control so the extra ice shield helps a lot. Also note that pretty much all of the creatures can be killed by two Rain of Fires.
time/life:
Freeze is better for pharaohs, and killing scarabs one-by-one isn't really effective if you leave their pharaohs alone.
Steam Machine can't be killed if their field is cleared. Extra phoenixes would actually be a liability against this AI.
Rain of Fire easily clears the field as long as you save them until they have 3 scarabs out. With this, their Empathy Bonds are useless and you can save your Deflagrations for Procrastination.