I think you will love watching Kai interact with the characters ! If at first he is a little shy talk to the cm with the next character and they then get the character to sit so they are smaller and the interaction is soo gentle it will win any small child round !!
Really hope in the next few days you get enough money from ebay to not impact your trip !!
It all sounds rather amazing .... and it will be lovely to see it all through the eyes of a little one. I am looking forward to having grandchildren for this very reason.