thank you for this; the advanced initial setup finally worked for me after battling all last night trying to get the "simple" version to work on my mac. the only thing that's still going wrong is that i am not getting sound, but that's for another post; i think i saw something about that earlier.
something you might want to add to the tutorial, since we're now mostly modding 1.7: in the arguments for the "run client" configuration, one needs to type
--version 1.7 --tweakClass cpw.mods.fml.common.launcher.FMLTweaker --accessToken Player1234
because 1.7 needs the access token, or the client will die.