Really? How does that work? Do you just walk into the shrine and declare, "I'm the priest now. You, get out."
In the "Please help with a small bit of history" thread, there is a comment that the Omoto Kyo sect requires all of its members to go through training of a priest (his involvement was 10 years ago so his information might be dated). This training lasted a week, and Steven Segal has claimed to be a shinto priest before, so it isn't that outrageous considering O'Sensei had a shinto shrine in every dojo he owned since his involvement in the Omoto Kyo sect.
I am personally a bit of a history buff, so any information you have on the subject would be appreciated. I am basing most of my information on O'Sensei's religious background on "A Life In Aikido" by Kisshomaru Ueshiba, "Essence of Aikido" by Ueshiba, Morihei, and "Phylosophy of Aikido" by John Stevens. What evidence do you have to support he was not?