Possible Clues:

• One who's got something coming (and a homonym for 8- and 34-Down)
• One destined to receive
• Inheritance factor
• Vita's legatee
• The legatee of Vita Sackville-West
• Property recipient
• Spouse or child, often
• One bound to succeed -- that's the irritating part
• First in line
• One who'll succeed in the ironworks