So many great questions, but I sadly don't have many answers. I will try though.
1. I am not a vegetarian nor was anyone else on our trip but I did hear them discuss vegetarian options a few times but didn't pay much attention.
2. We stayed in three different hotels and I don't think any of them had self-service laundry available, but I believe laundry could be sent out for an additional charge.
3. I'm not sure what you meant re: the internal flights and carryons. We both checked bags and had carryons.
ABD allows one checked bag, one carryon, and one personal item per person.
4. We are a family of four so we had two rooms in each hotel. The rooms were quite spacious and each had two beds. Not sure if you are looking for three beds though.
Feel free to send more questions or follow-up questions my way! It was really a great trip and it was our first ABD so it was quite special.