1) the rinnegan allows the user to use ONLY the base elements plus yin and Yang, according to jiraiya. Since he trained nagato he is a better source of information than Ibiki, who is running off rumors and legends. Also, you have yet to provide actual proof of Nagato or Madara using a bloodline limit beyond Madara's use of mokuton, since that was granted by his incorporating Hashirama's DNA into his body.
2) you forget that one of the gates heals damage to the body. So, again, Gai using Morning Peacock is within the realm of suspension of disbelief.
3) that is the argument. You claimed that gold doesn't have magnetic properties when it does, just not the properties Kishi was showing. Also, what you said about the "manga explaining how the magnet element works on gold dust" was never said. You pulled that out of your ass. Though it could be argued that Gaara's dad was surrounding the gold from all directions but the one he was trying to move it in, thus negating the opposite field's impact on the dust movement.
4) show another Uzumaki whose hair turned white from overusing chakra. Note that the elder and elderly Mito do not count as they were of an old age. Until then, Nagato's hair turning white was a unique occurrence and does not help your case.
5) when was it ever stated that the Akamichi descended from the Sage? The only known clans descending from the sage are the Uchiha, Senju, and Uzumaki. And for the last fucking time, their body expansion techniques are NOT a bloodline limit, they are hidden techniques taught solely inside the clan.
The only part of your post I can agree with is Kishi not using science properly for certain aspects of the manga.