I might be extremist to a point but I feel reviews should not be removed unless they are either diffamatory, reveal confidential information or reveal information who could identify a person. Same with somebody leaving the business; removing the reviews will no longer affect hobbyists since she's no longer available and having reviews erased will ensure nothing will backfire in her future.
Of course, some SP will refuse to be reviewed but, this is a REVIEW board! It's then a jugement call from the hobbyist to review or not. She's expressing a wish but hey, it's a free country! If the hobbyist have some class, he will respect her wish, unless he feel she was really bad. In that case, following her wish would just defeat some of the purpose of this board: helping hobbyist make good choices and assist in protecting them from bad services. If you go at a garage and they wreck your engine, will you agree not to mention it to anybody?
We see a good example of this with an SP in Ottawa who call herself "Fun V...". As soon as somebody ask info about her, the thread vanish... Rumor is she's not the best but who know? Result is, the rumors will never be defeated or confirmed.
Putting a list of who doesn't accept reviews is great but, ensuring the list will always get checked will get pretty complicated, with newbies posting, SP added at random time and plain everybody forgetting to check.
Bottom line: No reviews should be removed unless as cited above. What's written stays written. If the SP see false information on a review or something she disagree with, she just have to post her point of view instead of crying to get the review erased. If there is a bad review and the SP ask for it to be removed, she obviously know the review exist so, she have an opportunity to defend herself. If she decide not to defend herself then, no crying to the Mods, just tought luck. If an SP insist so much in getting a review removed without defending herself, we can believe chances are the bad things said were right!
Just my opinion. I'm open to debate but not to flames.