kitchen sink rough plumbing

Thanks for the information on the waste pipe size. One more question...when bringing in the waste pipe is there a standard height that I should bring it out of the wall? Would I be better off bring it up thru the floor ? And ,if so, should it be center of sink or offset a little for less trouble in getting the trap in?

The reason I was going to use 1 1/2" for the waste is because I have a cast iron fitting cemented into the basement floor with a 1 1/2" galvanized pipe leaded into its hub. Is there a way to chop out the lead and increase the pipe size to 2" without changing the cast iron fitting?

The diameter of the plumbing from the Main sink IS 1 1/2" which then connects to 2" waste pipe. Bob Villa or not - to suggest 1 1/2 is only found in 'bottom of the line' housing is inexcusable for a man supposedly in the know!
'Code officials' ???? So.....the 'inspections' when you buy and sell a home must either be incompetent or dishonest.

The under the sink plumbing attached to your sinks Main and Food preparation sink (preparation line will invariably have a disposal unit) is 1 1/2 inches.

I dont see a problem with going with a 1 1/2''pipe. Personally i would go a little bigger but worst case scenario there are plenty of affordable options to clean out your drain if it fills up. Things like drano were made for instances like these.