Possible Clues:

• I explain model being kept by former lover without much money
• Explainer of complicated ideas or theories
• No longer badly off, having accepted position, one explains
• It makes it sound easier provided exhibitions follow one up hill
• One shows it in poor sex novel
• Demonstrator in former Post Office riots in trouble
• One spells out world fair riots with difficulty
• One setting out poor - exist with struggle
• He'd set out formerly to squat in third-rate housing
• One who interprets international shows I mount