which direction do you take in west aust.

Q1 depends on time of year,Summer do south first, if winter do north first Q2 Perth dos'nt have a wet season weather, is about the same as Sydney only with out the humidity. Q3 Depends how much time you have, you could spend a week or 2 months down south. We went south a few years ago 1 week from Perth down to Albany then worked our way back to Perth & flew home, only saw a few tourist things, could have spent a month easyRegards Bob
Where to next

The wet season for Perth usally starts about easter.In the north west the cyclone season or the wet is coming to an end.
The south west region has almost perfect weather for the next 2 months or so at least.

"Should you spend more time there than on the top west coast?"

Thats a hard one. Both offer equally spectacular scenery and adventures but travelling in the north means long distances between places of interest so have unless you have oodles of time you spend most of the time in the car with a sore bottom.