I went to school in K-W. You'd pretty much have to put a gun to my head to get me to go back there. I'm not a fan of the landscape or the community. I don't do flat well, in either circumstance.
York could mean quite a few different things in terms of Toronto. East York, North York, then there's old York Region (I don't think it exists other than as a ward anymore).
Go to gasbuddy.com to check out the gas prices. Great site.
Depending on the precise location you pick, house prices can vary enormously. My house would be $100,000 more 3 blocks south of where I live, $30,000 less 1.5 blocks north, close to $700,000 more about 15 blocks south.
Toronto's got water, which was one of my problems with K-W. You can sink in a boat in Columbia Lake in Waterloo and only be up to your waist in water in the deep end. The beaches at both ends of Toronto are lovely, with good access. You could do much worse than to live near joeblow - she's got it made in the shade in terms of water access. Gorgeous area.
I transit to work in downtown Toronto. About 20 minutes in once I've walked to the subway, usually about 5 minutes longer going back. I made access to 24 hour public transit a condition when I was looking for a house.
There seems to be plenty of work in Toronto - help wanted signs/ads everywhere you turn. From retail on up.