Chelle, good questions. I know some of the answers & will have to check on the others & report back.
1) From memory I think the main goes to the top with no Y & no complex branch offshoots. But I will need to check to make positive I'm correct in that statement.
2) NO, there are no cavities in the tree.
3) I have not observed any other specimens in the vicinity --- however I'm in the process of going one by one through all the trees on the property to ID & log exactly what is there. And I can say with 99% accuracy there are no others like this on the property nor within viewing range of it.
4) That's the sticking point --- the leaves do not seem to be thick-ish nor leathery & certainly not near as thick or leathery as magnolia.
5) I absolutely get the feeling the tree was a natural occurrence & was not planted there.
6) No, there are no shoots growing around the base of the trunk.