A trust fund is a legal document and as such infinitely flexible. So it can be set up so that the creator can cancel it and take the money back or it can be irrevocable, in which case it can't be canceled. Even if it is irrevocable, it can still have controls on it, where the trustee has some discretion in how or when the funds are used.
Yes, but only if the guy who created it is still alive. The answer is probably "no" if creditors are relying on it or the trust itself has legal obligations to others.