6:
You are correct in noting the brochah on pineapple and banana id Hoadomoh. They are brought to the table for their ascetic feature. They beautify the platter. And if the rebbe (or anyone else for that matter) eat from them, they get to make another brochah. Nothing wrong with adding another opportunity to fulfill the daily requirement of making 100 brochos.
P.S. Quite some time ago, the frum communities in Europe hardly had exposure to tropical fruit. On occasion, someone managed to bring in a shipment of bananas, and were informed that they grew on a tree. It was a common mistake to recite a boreh pri ho’eitz on bananas. Eventually, someone investigated further and discovered that this does not qualify as a tree and that one should recote boreh pri hoadomoh.