I just came up with some other things I would like too see.
While unlikely I would like to see Kenpachi use at least Shikai, and hopefully Bankai. But I guess you would have some sort of power problem here, seeing how powerful he is even without shikai, or bankai for that matter. Yet we know his sword is a zan, because he says he can feel it's joy for fighting. He tries talking to it, like he wants more power, and like he wants to awaken it.
It would be cool, tho it wouldn't really matter, to see Yachiru do some fighting, we know that she is fast at he very least. But I don't think I have ever heard of any qualifications for those who become vice captains, like there is with the captains which for example need to be able to do Bankai(ofc Kenpachi is en exception) so Kenpachi might just have given her that position just for lolz or because that means he can take her with him everywhere he goes, like missions and meetings and all that.
And well after seeing again that Ichigo learned to make that cannonball which is a type, or takes use of demon magic I could actually see Kido as a possibility for him. Only problem is that he would have to learn it all the hard way, it really really really would not fit Ichigo to run around saying the whole sentence for the magic even if it is a very high level spell. Tho it would be awesome to see him run around like "Way of Destruction no. OVER 9000, Nuclear Bomb!"