Have an easy to understand Graphical User Interface.

Keyboard commands aren't the reason I want Sublime Text. I want it for the amazing plugins that support a load of features as well as having a graphical user interface.

emacs has an easy to understand GUI (as an example, here's a screenshot of its gdb mode: https://www.gnu.org/software/emacs/tour/images/gdb.png), and amazing plugins that support a load of features.

There's a reason people have spent so many years using it.

I use the Emacs GUI, but would not call it easy to understand because it differs so much from most modern GUIs (i.e., most GUIs designed after the Mac became the most popular platform for GUIs around 1987).

For example, if there is already a selection, right click in Emacs extends it much like pressing a shift-arrow key does in a typical GUI. (Most modern GUIs will of course pop up a contextual menu in that situation.)

Similar to the keyboard-driven part, as much as possible of the GUI part of Emacs is implemented in Lisp, so it seems to me (as someone who has modified his copy of Emacs to pop up a contextual menu on right click) that it would be fairly easy to write a GUI for Emacs that adheres much more closely to modern conventions than the GUI that comes with Emacs does, but the only project I know of that has tried to do so is the Aquamacs project.