I can't answer the first one, but for your commercial zones, try placing a lot of fountains around the zones...close access to subway stations that connect commercial to residential to industrial helps, too.
Anything that looks crappy like Power Plants should be kept far away.
Basically, every cube of any zone needs to be within 3 or so cubes of some form of transportation...if you zone a huge 12 X 12 block and the middle cubes are not within the 3 or so cube range of a street or subway station, that area will never develop.
That's how it was with SimCity 3000, anyway.
And Metal Gear Solid 3: Subsistence...