By simple I mean the UI, is simple, using JavaScript so heavily for the additional features was a way of keeping the interface simple, it hides away the functionality of HFS, until you need it. The code may be complex, but it creates a simple user experience.
There are several reasons I chose to have small one line comments. The main being the room available, you could make the tooltip take up two module areas (just have to adjust some numbers), and end up with a larger paragraph block of text viewable. As for not being able to format the comments, its a limitation of the tooltip implementation - and not one I plan to remove any time soon. The other way of doing it, required even more HTML, increasing the DOM and complicating the javascript further, it was crashing browsers. This method is enough. I could possibly enable line breaks in the next version, but it was purposely limited - considering Live 3.0.0 had zero comments, this is a massive improvement.