Track record in context
Ask for realised outcomes, not just current marks: how many vehicles have completed a full cycle, what was returned, and over what period. Unrealised valuations are estimates and should be labelled as such with a method and date.
Alignment
How much capital does the sponsor contribute? Are fees charged on committed or invested capital? Is promote paid only after investors receive their preferred return and capital back? Are fees to sponsor affiliates disclosed?
Reporting discipline
Ask what an investor receives each period, when tax documents are delivered, and how questions are handled. Ask what happened in the sponsor's worst deal and how investors were informed. The answer to that last question is usually the most informative one.