1, i was SUPER confused by that to but the reason is when naruto sealed the kyuubi in naruto before he died he also sealed SOME of the kyuubi's chakra inside himself *my thought so it won't be a HUGE pressure on naruto and die*
2,when kakashi saw naruto KCM run fast it looked like a yellow flash that's why he thought it was Minato not because he looked like him in KCM but because he had the speed and the looks
3,he released KCM in the battlefield *in the manga* because he had to do it to protect his family friends konoha world etc... he didn't do it before that's why people said he's either crazy or a genius
4,^
5, Kurama hated everyone because Kurama is the essence of hatred extracted from Juubi just as Shukaku is the essence of loneliness but from what i see he's kinda friends with naruto now and minato is using the chakra he extracted from the kyuubi back then he forced the cloak Current Kurama didn't give him the power
hope this helps