The Preferences menu item is grayed out because there is no preferences dialog box yet. It sounds like you're asking for a number of different features, though. Edge Code is based on an open-source editor called Brackets, which is updated more frequently -- so some of the features you're asking about are available already in Brackets even if you're not seeing them in Edge Code.
More specific responses:
- Dark color scheme -- this is available in the current Brackets release (View > Themes in the menu).
- "HTML and CSS codes in colors rather than plain black and white" -- if you're not seeing color-coded CSS & HTML files in Edge Code, that's a bug. What is the file extension of your files? If you look in the status bar in the lower-right corner, does it say "HTML" or "CSS", or just "Text"? Can you post a screenshot of what you're seeing?
- View two files side by side -- this will be available in Brackets release 0.44, which is probably due out in late September.
- "I have to physically move my hand to switch views" -- you can switch files without taking your hands off the keyboard using Ctrl-Tab / Ctrl-Shift-Tab (next/previous in MRU order) or using Ctrl-Shift-O (to filter on filename or a subset of the filename).
Hope that helps,
- Peter