Re: Ichigo's bankai
I think Ichigo's bankai still has a long way to go. He learned in a rush, we all can agree on that. They even mentioned how it takes years upon years of training to fully master your bankai. I think we mostly are just seeing him tap into his power without much focus.
Byakuya, Hitsy, Renji, Urahara and other have multiple attacks with their swords/bankai because of years of training and mastery of their shingami powers. (Don't know for sure Urahar's bankai yet, but he has to have someone awesome up his sleeve or under his hat)
Ichigo needs hardcore training on mastering his shingami powers, which he really hasn't had since Urahara trained him.
Vizards trained him to control his mask and tap into is Hollow Powers. The rest of his training has been field experience and finding sneaky ways to release his GT in his opponents face.