Hello,
1. Yes
2. Yes
3. At the time when the vendor withdraws a commission, the commission amount is calculated at that time, taking into account the market rate at the time of the withdrawal, not the time of user checkout. In other words, the actual value transacted matches the fiat value paid by the customer in crypto. A vendor then does not have any incentive to wait for the “best” time to withdraw, by observing any fluctuations in the value of the cryptocurrency.