Madara also stated that Black Zetsu was his will, and that the flower needed to bloom in order for the Mugen Tsukuyomi to work. (He stated a lot of things, most was proven wrong in the end.) Also, even in the VIZ translation, it was never stated that the Shinju spoke. Not even once.
Legends are created by people, instructions are created by creatures with a mind and traditions comes from generations. The legends on the Shinju was written by Hagoromo, and was stored in the Uchiha Tablet. The instructions were given, but neither translation states if it was the tree or someone else. The tradition would have come from the previous generations of people. For your comment on only someone having to be "worthy" to give instructions. Well that could be anyone, a King, a priest or just traditions from ancient times. You again, have no proof of your claims and your "interpretation" is as faulty as you claim mine to be.