Questions, problems, and anything that looks wrong:
A person reads it. If you are reporting something broken, the app version from the account screen and what you were doing at the time will get you a useful answer faster.
The guide covers how sharing, time zones, and places work. Two things surprise people and are both deliberate:
iOS only learns which links belong to an app when the app is installed. If the app was already on the phone before this site started serving invitation links, reinstall it and the links will work. The code on that page always works in the meantime — type it into Join a trip.
You can do it yourself, in the app: Account → Delete account. It removes the trips only you can edit, takes you off the ones you share with other people, and removes your name and email. There is no undo, and you do not need to email anyone to have it done.
The guide has the details of what goes and what stays.
A trip is only visible to people who were given a code for it, so there is nothing public here to moderate. If somebody you invited is using a shared trip to harass you, any editor can remove them from the Share screen, and codes can be revoked. If that is not enough, write to the address above.