Naruto hands down Though Lee has a few trick up his sleeves like opening the gates. But even at his eighth gate, Naruto's Sage Mode + Nine Tales Chakra will eventually demolish him.
Obviously Zaraki. He has so much pressure that the little flowers of Byakua will just blow away. Besides, Zaraki has much more fighting experience and showed proficiency in fighting with two Captains at once. He also defeated No. 6 Espada, but Byakua barely mangaed to beat No. 7
I think tou are right. But I'm more of a Sasuke vs. Naruto fan. So little stuff like romance between low characters doesn't concern me. But I think that your assumption is correct.