I've had the same experience with editing text, it gets really frustrating at times. I often find it's faster to delete chunks of text and rewrite them rather than edit. (I type reasonably quickly on the iPad.)
But now that I think about it, if you actually have a keyboard attached to the device this is a solved problem. Just port emacs or vi.
Why port? Just ssh to a terminal somewhere in your university. Pop open emacs/vim and typset with TeX. I did this with my netbook a couple times. Even let me print the paper.
But now that I think about it, if you actually have a keyboard attached to the device this is a solved problem. Just port emacs or vi.