mel_996,

Your plan is good and quite do-able: "3-4 days in 5 different places"- maybe even 6 places. You should be able to "see a bit of everything and get a real feel of what the places are like"

But, you say: "We don't know where we will fly into". Qantas flies to LA and San Francisco. While San Francisco is on the west coast (and maybe you've already been there). It is the best, most loved, fantastic city in the USA (ok, maybe NYC is, but clearly No other place comes close!). It seem a shame not to visit when you are already there. It's like not visiting Sydney after flying into Kingsford Smith.

With all the places and activities suggested here, consider staying about 3 months.