>>When we don't use cheese, the sauce is always too sour.  What
>>ingredients can I add to make the sauce less sour?
>I hate to say it, but it needs some sugar. Not much, but try it.

My Italian partner uses his grandmother's recipe for sauce, and she always
put just a little sugar in it, to smooth out the flavor. I was surprised at
first, but it works, and that may be the taste you're missing.
You can make a quick light sauce, with canned crushed tomatoes, that doesn't
need sugar; just toss together the tomatoes, and whatever veg you like,
mushrooms, black olives, garlic, etc. You can heat them all up in a saute pan
first if you like, but you don't have to. And this may sound odd, but try
some canned drained cannellini beans. They're great, and they add lots of
richness and creaminess to a pizza.
re: dough: I've never used milk in either pizza dough or bread. I have a good
recipe for  dough which came with my baking stone, of all things. I can mail
it if you'd like it. Also, the bread recipe on the back of the King Arthur
All-Purpose Flour bag makes great bread and uses no milk.
Libby Rock