To be honest, I don't think you'll lose a huge amount if you've already been on plan for a bit. I only had 6 lb drop, which I think was due to me doing a quasi-SBD ahead of time.
As to tomatoes and V8 juice, I don't have the book with me right now, but I believe that tomatoes are allowed but in limited quantity. I think it is 1 whole tomato or 10 cherry tomatoes per serving. The reason for the V8 juice is to help people get a jumpstart in their daily serving of veggies. If you can do it by eating veggies instead of juice, all the better, but some people (like moi) don't like veggies for breakfast so V8 is better than nothing. Plus V8 has lots of potassium, lycopene, and other good nutrients.
Congrats on starting Phase 1!!!