The thing is, you would only be sectioned in pretty extreme circumstances - and then of course it's regularly reviewed, it has to be by law. If you were able to view the situation from a rational viewpoint you'd probably want to be medicated and taken care of. After all sectioning isn't about imprisonment it's about patient safety. They want to keep you alive and will do their utmost to make sure you don't want it any other way. So perhaps this is a question of quality of care? If you go to a hospital with a good track record and proven success rates I don't see what problems lie ahead. Voluntary patients usually have a lot of freedom and low observation so there's plenty of time to get on with recovery and ask any questions you need to. You should also be able to request a copy of your treatment plan at any time if you have concerns.

My advice would be to pick a hospital with a good, busy programme so that most of the time you'll be too preoccupied to catastrophize.