@Aurielle-and-Dave0 "Can anything be done or am I held hostage by the potential for a review?"
Being held hostage over the potential for a bad review isn't an objective situation- it's purely subjective- your own attitude.
Hosts who run their business with this attitude end up feeling like doormats, running around trying to please entitled, demanding guests, or losing money by refunding guests in contravention of their own cancellation policy. And it doesn't work- those kinds of guests tend to leave bad reviews anyway.
Just keep a polite, but firm and professional stance with those kinds of guests and try not to concern yourself with the review. There's really nothing you can do to stop a guest from leaving a bad review if that's what they are determined to do just because their every demand wasn't catered to.
There are hosts who fret about every review until they see it published, are super upset if it's not a glowing 5* review, and hosts who don't put any energy into worrying about reviews. If they get an unfair one, they just leave a response that makes any misrepresentations or lies clear to future guests and move on. Guess which ones find hosting less stressful?