A 100% accurate Freeze move wouldn't be anywhere near as broken as Spore has been in this generation because it wouldn't work in the sun and anything with Scald, Flare Blitz, Sacred Fire or Flame Wheel (lol) is practically immune to freeze. Incidentally pokemon with those moves are water and fire types, both great switch-ins against ice types.
Precisely. Freeze mechanics can easily be tweaked. It strikes me as odd how on the type chart fire, grass, electric and ice are next each other each having an immunity to statuses that can be afflicted...seem to hint at this. They also seem to emphasize statues a lot in this gen and game mechanics in general.