He needs to stabilize his 4S and focus on polishing up other aspects of his performance rather than solely concentrating on jumps. In a documentary, Brian Orser expressed his exasperation with Hanyu being so single-mindedly focused on just his jumps.
He brings so much passion and raw energy to his performances. I'm looking forwards to seeing his skating develop.
I think his toe jumps are better than his edge jumps (his 3A is an exception)? So maybe a 4F or 4Lz instead of his 4S? 4A is really pushing it. I think he can probably do it but I don't really want to see him do it. It's a very risky jump. Maybe he can pull it out towards the end of his career?
Oh please no. I get so worried about injuries for these skaters. A 4Axel would be begging for injury. His 3axel is perfect enough. I'd like to see him develop more on the second mark. I could watch Daisuke, Kozuka skate all day. He needs to reach that level.
^It was in this documentary on YH on youtube (can't find it right now) where Orser said Hanyu had skills in abundance, but he needed to build a better foundation and polish up everything else outside of jumps. Then after one of Hanyu's horrible performances (Worlds 2012?), Orser said that now maybe Hanyu would start listening to him about focusing on building a robust foundation first, then focusing on quads.
Edit: Here it is! http://www.youtube.com/watch?v=WsW8ex-Ii1o
I don't remember Orser ever saying what you wrote at the end. He of course focused on foundation, and it's true that at the beginning Yuzuru didn't understand, but he always did what he was told to do and started putting his utmost effort in skating skills. He was not convinced, but he still did it. If you meant Worlds 2013, Orser said that because of injury and asthma it couldn't be helped.
As for quads, he says he now rotates both 4Lz and 4L, so he might try them in competition in the future.
I don't think 4A is a good idea, too dangerous and risky for the knees. But 4Lz and 4L might be possible. I do hope to see skaters execute these jumps in competition.
The 4Lz isn't the FIRST jump in the world. He won't be interested in that. And the 4F is hard to avoid "e" for him. Hanyu is likely to succeed the 4Lo in next season and make the guiness book of world records. When he doesn't have motivation other than that, the 4A might be an option.
If he practices a quad loop... it will make his triple loop seem incredibly easy in comparison, and he might get higher GoE for it :-DI don't know about a 4L... his loop is one of his poorer triples. But one can hope! I think Reynolds if he continues will be the first to land 4L.