Brasslite has a Vargo titantium pot (.9 liter) and a Vargo mug (750ml) at substantial discounts: $35 for the pot and $30 for the mug.
For your other questions:
1. using the "cook" pot (or "cook" mug) to boil water for rehydrating a meal in a plastic food bag helps cleanup & keeps the pot (or mug) clean for prep of hot drink;
2. a separate insulated cup (about 1.5 oz) keeps hot drinks hot longer -- and keeps the "cook" pot clean (if those benefits are worth the extra 1.5 oz);
3. ziplock baggie containing dry cereal, powdered milk, and dehydrated fruit does for breakfast -- just add H2O to the bag's contents, smush it up a bit, and eat.