You're right - definitely not a restaurant, though they do have tables if you don't mind keeping your coat on!
Happy to second your recommendations of Castle Chinese and Erawan.
I also had a fantastic breakfast at the Needlemakers recently, run by the people from the Roundhill pub in Brighton...
I thought Rustico was distinctly average when I got takeaway, but maybe we'd been spoilt by The Hearth which was absolutely brilliant while it existed. Best pizzas in Lewes are now the ones from the van under the arches at the staion.