AM Eugene:
What Heather said above is extremely important, don't omit the sulfite!! I have heard there are some wineries out there making wine with out added sulfite, but if you look on the bottles of store bought wine you'll see on the labels that they contain sulfites. Sulfite (potassium metabisulfite) is the key to keeping your wine from oxidizing and / or spoiling, stronger solutions are used for sanitizing (although there are other sanitizers). Some sulfite is actually produced in the fermentation process, so I don't believe that any wine, even organic wine, is completely sulfite free.
Once you've run through some kits and read some historical old posts here, you'll see that lots of folks regularly omit some of the chems for various reasons.
For instance, potassium sorbate is frequently omitted when your wine is fermented completely dry and contains no residual sugar AND you don't intend to back sweeten it.
Other folks don't add bentonite, or using clearing agents, preferring to allow time and gravity to their jobs in regards to clearing the wine.
I don't recall ever reading of anyone omitting sulfite, I could be wrong, but I would never do it. As Heather said, roll with the instructions, they'll get you to the finish line.