Ang,
I am so glad to find people who are doing SB!
I had the same question about sunflower seeds. I decided nuts and seeds are probably the same, so I ate them and I had a good loss after the first 2 weeks so they're probably okay.
I don't remember what he says about diet soda and art. sweeteners during phase 1, I'll have to check. I remember having a couple diet sodas in the beginning.
I love the flexibility of SB, especially the fruit, though I stick to the lowest carb choices like strawberries.
Good luck!
-J