a) besides the 17-55 f/2.8, there's the 16-35L and the 24-70L, but more expensive...
Some people say the Tamron or Sigma 17-50 f/2.8, not as good, but nowhere near as expensive.
other than that, you'll be using Primes. the 50 f/1.8 is a bargain $100, the 28 f/2.8 around $200, 35 f/2 at $300, 50 f/1.4, 20 f/2.8, 28 f/2.8 get up to half the price of the 17-55 f/2.8. Also Sigma make an APS-C only 30 1.4 around that price too...
b) yes, and it's called AF microadjustment. But only on the 50D (not 60D), 7D, 5D and the 1 series. Otherwise, send your camera and all your lenses in to canon together, i have no idea what it costs though (only pros get it for free if they buy enough expensive stuff)