Others have answered 2, but to 1: I'm a Vim user, so I used to write Arc code sans syntax highlighting -- the Anarki highlighter wasn't that good. I soon got sick of this, so over the summer I wrote my own highlighter & ftplugin, which I posted at http://arclanguage.org/item?id=10147. It's the most complete/up-to-date syntax highlighter I'm aware of, inasmuch as it works for me. I haven't had much feedback about it, but if you're a Vim user, I'd appreciate any input you have!
