I hope your not too young for this cruise, my wife and I are in our mid 30's and leaving on 7/12 for the st pete to moscow sailing!!!!
Give viking a chance, they worked very hard for us to get us the flights we needed... Next time you call, ask for ext 311... That is the person in charge, and her name is linnea. We found her very helpful.
Good luck, this is our very first river cruise also, and we do not know what to expect either.