Sounds good! You will need to let it thaw a bit to cut it. Make sure you use a long blade serrated knife and let the knife do the work. Take your time and remember you can always take more off, but you can't put it back on
You should be fine leaving it out once it is crumbcoated, seeing as you are in Melbourne, so long as you leave it in a cold place, not near the heater say! lol
What are you 'icing' it with? Buttercream or fondant? If you are using fondant, don't put it in the fridge or Glad wrap it. Leave it under a dry teatowel in a cool dry place.

ETA - Should add, after you crumb coat, leave it and let it crust over a bit before you ice it.