hey, i agree about the supermarkets. When i was in Paris (for some of the same reasons you were) they were a savior. pretty cheap food comparitably speaking but still food none the less. May i recommend a 2 or 3 water bottles. one for water of course another for a good strong drink and one more to chase it down.
im not really knowledgable on accomidations but a good place to really relax sit smoke and drink is jardin de luxembourg. wonderful.
have a good time
