Possible Clues:

• Raised soundly, and by nanny, to write such letters
• Living on a rather monotonous diet
• Living on sandwiches?
• Main source of income indicated in guest house, say
• Standard, as interpreted in accommodation, say
• Study in holiday accommodation, say, that's reliable
• Typical drunk bartender at Bud
• Routine learned in guest house, say?
• One’s main source of income
• Drab debutante dancing first part of rumba routine