The first point it's quite obvious from the gecko when Kisimoto added the number of tail power scaling system to the Bijju. It makes sense due to the fact Naruto with half of kurama's full chakra reserve of power was able to match 5 other jinchuuriki in power. I'm not underrating the other bijuu if Son Goku was there in the power struggle, I would ultimately believe it would tip the scale. Althoigh, Gyuki was there in the the battle as well with both of Kurama's and Gyuki combine their power would of end it. The math is there it would be plausible for Kishimoto to set it up that way.
2. That's simply Gyuki sticking up for Shukaku even due by feats states otherwise, so Kurama was being an a ahole even though it was clear as day he outclasses the other bijuu, and was the most important one of the group. That's why Madara went on a field trip to mindfudge Kurama theirs a reason why Madara went after him not the other bijuu.
3. No, completely wrong there it was a huge difference read Jinchuriki battle. It makes sense as in point one I made on how Naruto and Kurama was able to match the other 5 bijuu in power.
