I own DVC, but after being a owner I found a rent deal too good to turn down. The rental was 2 days added on to my DVC stay. The owner was in days of losing all of her points. Anyway, when I printed the confirmation, it had mine and my husband first names. No last name anywhere. When we drove up to the gate at BeachClub I showed the guard the confirmation with our drivers licenses, then the same at the desk. We also could not call Member Services, it was not our reservation.
If it were me, I would call the owners, get it straight. Have it faxed or emailed to you. I have had two confirmations where the cast members fingers could not have hit the right keys.
For the ones where the kids are not added, if you are using the dining plan or Magical Express, they have to be added. Disney wants the names and ages of all in the room. The kids will only be a number on the confirmation.
Don't feel you are troubling the owner, he shouldn't have rented if he didn't want to follow the rental all the way through.