Oil change interval is up to 15K miles. The EVIC will tell you when to change your oil... And if you're worried about the longer oil change interval, change it more frequently and/or getting a oil analysis done.
On the fuel filling, the problem is the 2nd flap on the fill neck. You have to make sure you get nozzle pushed in far enough past it to stop the burping. Many are stating that holding the pump at the 4 o'clock position helps.