This site collects what an account needs and nothing more. This page says exactly what that is and what happens to it.
Three fields, and no more.
Nobody outside the company. The list of account holders is not sold, not rented, not shared with a partner, and not loaded into an advertising audience. It is stored so that it cannot be read from a browser: you can read your own record and nobody can read anybody else's.
As long as the account exists, plus the time it takes to close it properly. Delete the account and the record goes with it rather than being kept for something else.
Write to contact@tradoshi.com and say so. Your address is removed, and we do not ask you why or try to talk you out of it.