Hi Lana! Welcome to the forum! This is a great place and you have some great questions!
There is a terrific thread in the stickies of the South Beach FAQs that has an updated Phase 1 food list. The book is years old and since it's been published, there have been changes to the plan, so you can find all of those things on this site.
Green tea is fine. Choose decaf if you can.
Pinto beans are also fine. Make sure there is no sugar added if you are buying canned, and always rinse canned beans to reduce the sodium.
The only things you have to watch out for when buying dressings are sugars and starches. I prefer to make my own dressings (which usually just consists of drizzling a little olive oil and balsalmic vinegar over my salad!). It's easy, and you can add whatever spices you prefer to the mix. Generally about a half tablespoon of olive oil and one teaspoon of vinegar should be sufficient for one salad.
Onions are fine. So are olives.
Phase 1 is designed to be a detox from simple carbs. In order for it to work, you need to follow it uninterupted for two full weeks. What you could do is put what you're doing now on hold (maybe add back in a couple starches, take the rest of this week as a trial for new recipes or something) and go to the night out and then do a full two weeks of Phase 1 after that. Phase 1 is supposed to only last for two weeks because it's not truly a nutritionally balanced plan, and that's acknowledged. The fruits and starches are taken out so your body can get rid of those sugar cravings, and then they're added back in one at a time so you can recognize which foods cause you to have cravings.
I hope that helps! Glad to have you on board!