I see no harm in discussing finances, especially the repair work needed on the garage. That has to be addressed and taken care of, i.e., the sooner the better in order for you to sell the home.
If you speak of finances, do not mention you saw the check about the OW. You don't want to tip your hand as to what you know and have seen.
Learn to play your card game properly, i.e., keeping things close to the vest and when to fold. Right now, your cards need to be kept close to the vest.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
