Can I really have as much of the soups as I want at any one sitting or should I have measured portions? No. Measure out one cup and eat that. If you're still hungry, you can have more. Odds are, you won't be hungry. I wasn't measuring, I just scooped it out and ate it. Turns out I was only eating 1/2 cup and I was filling up. The soup recipes provided are REALLY filling (especially the split pea/Ham and the Lentil Barley).
Can I have canned soups? Personally, I'd stay away from the canned soups solely because of the sodium content. I'm a purist in the sense that I like to follow programs to the T. The recipes provided are proven, why try something else that may or may NOT work? Besides, as mentioned above, the home made soups are really filling (not to mention, pretty yummy!)
jello and pudding? how much and can it be store bought in the little cups or should I make it from powder? I was SHOCKED the other day when someone mentioned the carbs and sugar/sugar alcohol in the little cups of the pudding. I HAD been making it from the instant powder and assumed they were the same. THEY ARE NOT. Stick to the instant powder stuff. As for the jello, check the packages and see if they are the same. If not, go for whatever has the least carbs/sugar/sugar alcohol.
Oh...and GOOD GIRL!!! You sound like you have the right mind set now!

Rock on!