I see. I switched from emacs to vim years ago and now I've forgotten most of the key chords in emacs. Nevertheless, seems like an awful way to edit files on a small android device. I tried vim for android and it was quite challenging. Not something I want to repeat.
With "Unexpected Keyboard" (from f-droid) it's ok. I've come to expect that there's a basic choice between easy, with GUI, and powerful (like "sort a region of lines"), which is only GUI if you've got a powerful GUI, like plan 9. Otherwise, powerful means keyboard-driven.
When I've got a long, complex edit, I've got a nice, pocket-size, battery-powered folding bluetooth keyboard; combined with the kickstands on my phone cases, it is pretty good.