The appearance (both the text font and the UI chrome icons and colors) really is not to my liking. I see that you can already change the foreground and background color of your document. Any plans to add more options?
You should be able to change all the colors in the theme options! As for fonts, currently working on adding options there! Probably not going to support custom icons though, but maybe an minimal mode (sans icons, maybe only text) could be interesting?