You're right that those terms are unclear, as written. That's a result of the developers having to squeeze the text into the label area without much room. In the future, we'll change the text on that page to make it clearer.
You've pretty much guessed them correctly pretty much across the board.
Here's a full explanation:
"First Payment Percentage" means the amount of the total charge that you want to be collected at the time the guest accepts the quote. So if you want the to pay the entire amount up front, you'd enter 100% there. If you want them to only pay the first half, you'd put 50% there.
"Second Payment Days" means the number of days before the arrival date that the second payment will be collected. The second payment is scheduled at the time the guest accepts the quote, and the system automatically collects it. You don't have to remember to come back or bug the guest again. You'll receive emails on that day if the payment succeeds or fails (as will the guest).
"Days Before to Reserve" is the number of days before the arrival date that the security deposit will be reserved. The security deposit is not collected in the sense that a payment is collected from the guest's credit card. It's merely a hold that is put on the card.
"Days After to Release" is the number of days after the departure date that you (the owner) will get an email from the system telling you to release the security deposit. The security deposit is not automatically released because the system does not know if the guests caused any damage to your property. The system sends you an email as a reminder. The release process is a very simple (one click) form that releases the security deposit and sends emails around.
Sorry for the confusing language.
