The second number is the DME reservation number. As for the misspelled name, it doesn't matter for DME, but if it does for you, by all means just use the marker to correct it. Just do not obstruct the barcodes. As for the flight... inbound doesn't matter. And like they said, they can re-print the vouchers at the Welcome Center... and you'll get another copy the day prior to check out. I've used the DME system... it handles change just fine. It's just easier for all parties involved to have it taken care of at the airport. If they were to re-send you out stuff now, it might not get to you in time, and then you'd be worried. And even if it did, that would now be extra tags to get confused with the old ones. The Welcome Center can do the same thing, with the same effect, with much less confusion.