Here's a list, conjured on-the-spot:
Is it a playtest review, a review based on a complete reading, or something else? What else?
Do you know any of the people involved in the production of the book (or other product)? If so, in what context?
Are you, or have you been involved in the RPG industry at all? If so, in what way?
Is the review in question of a product you received a free copy of, or one you bought? If it's a free copy, why is that so?
How many RPG reviews have you done? Of what? Where can these reviews be found?
Have you done any other types of reviews? If so, what and where?
Do you play, GM, or both?
What systems do you play and/or GM?
How long have you been a regular roleplayer?
How often do you roleplay with each system/campaign type/group?
What playing/GMing styles do you and your co-roleplayers generally adopt/prefer?
Does 'fluff' or 'crunch' interest you more? Why?
Do you have a favourite RPG company? A least favourite?
What is your favourite RPG system? Your least favourite?
What is your favourite RPG campaign setting? Your least favourite?
What is your favourite RPG supplement? Your least favourite?
There are probably others that are highly relevant, but these would do nicely I think. Some of them would obviously have to be answered in each review; others could be kept 'on record' elsewhere.