I voted smaller bezel and more RAM. The processor is already plenty fast enough for me but more RAM would do a lot more for keeping the iPad smooth and future-proof. Smaller bezel would give me either a smaller iPad or a bigger screen. I'd be happy with either as long as the iPad doesn't get any bigger.
AMOLED screen would be nice, mainly for watching movies, but not necessary.
I only use 3D Touch on my iPhone for the keyboard trackpad, which the iPad already has with two fingers.
Faster Touch ID and the new home button would be great to have, but hardly at the top of my want list.
I don't need longer battery life but I wouldn't turn it down either. As long as Apple can keep it around 10 hours, I'm perfectly happy with that.
Really, I just want more RAM and a new design with smaller bezels as long as whatever design they go with isn't ugly.