Hey, I did read Ultrametabolism and I remember liking it - but it's been awhile. If you're looking for a healthy, whole foods salad dressing, you can easily make your own (tons of great recipes on the web). I like Annie's Gingerly Vinaigrette (organic, low calorie, low fat).
I can't answer the rest of your questions based on Ultrametabolism, but for me - I put the occasional splenda in my coffee, I drink the occasional diet soda and it hasn't stopped me from losing weight or keeping it off.
SIX YEARS at maintenance weight!
My very long weight loss story
"I saw an angel in the marble and I chiseled until I set it free."