Horizontal scrolling is almost always a bad experience for the user. But 80 is way too restrictive. I'd say no more than half a standard monitor wide is the character limit. What's a standard monitor depends on what's used by the devs writing the code of course.
> Source code should liberally use Unicode symbols.
Give it a few years. But make sure there's a good normalization (there are several ways to print the same glyph on the screen that are different bytes in memory)