An AMBULATORY person is an ABLE bodied person, so:
Can you refuel an aircraft with an ambulatory person on board? NO.
(unless there are excemptions etc, but that won't be in the PPL exam)
There will be a small number of Human Factors questions in there.
Might be one on Looking down in the cockpit whilst turning, then looking out the window and how that might affect you - should be logical if you've studied that bit.
Also, make sure your first and last light calculations are accurate and that you can confidently convert from EST to CST to WA time without error. These are multipart questions and you'll lose a lot if you get them wrong so be careful with them.
Make sure you know your Density Height calculation - from memory this can't be written on anything that you take in and it's not in the VFG.
If I recall correctly, you can take in your VFG and ERSA - the VFG is extremely handy and I would go as far to say that 70%+ of the answers are in there if you know where to find them. Make sure you know where to find the weather forecase bits around Inter and Tempo etc and the refuelling distances etc.
From memory there was a confusing question in there about flying at 1,500ft and the requirement for position fixes - I might need a reminder on that one.