8. What if I sign a 'Form 4' with an agent who shows me a flat, and later, I buy the flat through another agent or directly from the vendor?
In that case, you must also pay a commission to the first agent. See Schedule 3 - Commission to be paid by Purchaser in your estate agency agreement ("Form 4"). If you anticipate possible dealing with the vendor directly or another agent, then you can shorten the validity period in your agency contract so that you can appoint another agent afterwards.