- Great.
- The hair itself is imbued with chakra to harden it and sharpen it. If he tries to cover it with his face, he'd rip it apart. Since he can't cover it because of this, Amaterasu would spread and instantly overwhelm him. Even if he
could cover his face, Amaterasu would still burn straight through it when Itachi focuses on the flames to intensify it. It easily rendered CM2 wings that tanked high-level Katons to ashes in literally two seconds. I don't see why it can't burn his hair.
- When he summoned it he appeared on top of it. Since Amaterasu spreads, it'll spread on him easily. He'd have to jump off of it to avoid it, and when he does this, he's prone to get hit by Amaterasu.
- The fact remains that Jiraiya has never used Kage Bunshins in a serious battle and, even when it would of blatantly proved highly beneficial to him to do so, he has not. When Itachi and Jiraiya had their first encounter, Jiraiya never used a Kage Bunshin while fully aware of his Genjutsu prowess and that he was an Uchiha. There's no difference from both then and now.
- That's not a substitution jutsu. That's Shunshin to run and avoid getting soloed. He could of used a substitution jutsu, but he didn't. That's not how Jiraiya fights, so I don't see why he would suddenly start fighting in that way now. It's like saying Sasuke is going to start fighting like Ay simply because he finds his threat powerful enough. It's not happening.
- All of that is pretty useless when he already has his crow with a Sharingan positioned in the distance to watch all of Jiraiya's movements. Checking where to fire his Amaterasu is easy then. Besides, Jiraiya's Katon without Bunta was weak enough to be subjugated by Konan's basic paper style.
You must be registered for see images
Itachi overwhelming his Katon shouldn't be difficult. Besides, how would Jiraiya counter a Katon when he doesn't even know it's coming to him since the dust obscures where and what Itachi is doing? The best he could do is jump out of the way before it hits him and after it already cleared the dust. Itachi can also easily jump out of the dust and fire from there considering his elite Taijutsu and speed feats.
- He doesn't need to. All Itachi needs to do is engage in Taijutsu and once that happens, it's over for Jiraiya. He doesn't even need to do that. All he needs to do is Shunshin above him and fire from there. Even Bee, who has amazing reflexes and was able to respond to FTG, couldn't react in time to Itachi's Shunshin.
You must be registered for see images
Kabuto was able to easily dodge Sasuke's Susano'o arrow, which was so fast that Danzo didn't even have time to weave a single sign to avoid, and yet was blitzed by Itachi's Shunshin. Itachi closing distance should be no problem in the slightest.
You must be registered for see images
He blitzed three 3T precognitive users
You must be registered for see images
Jiraiya, who possesses less reaction time, agility, and speed than all of the people I've mentioned is not going to be able to keep up with him in Taijutsu AND he won't be able to out-distance him so he can't be killed by Amaterasu.
- Since the smoke bombs have no chakra, I don't see why Itachi shouldn't be able to see the color of Jiraiya's chakra through it and attack.