What's the point in making Emacs behave roughly like another editor when you can just use the original? Also, Emacs has about a million lines too much bloat for the target audience of Nano. Which is the one thing you can't fix by adding tons of plugins.
My advice to the author would be to give emacs an other shot. It can be configured to behave a lot like nano (and isn't modal), and runs in the terminal. But there's an ecosystem of plugins around it and has a lot of stuff that's built-in. But one day one of the journey it'll behave almost exactly as nano.