Notepad++ is Windows-only; I’ve been using Atom and it’s working great for me – I like have multiple scenes open at once in tabs, and it does a nice job of guessing when you start to type a variable name. I haven’t tried CSIDE or Chronicler; I wanted to learn to use a program I could maybe practice other coding languages on in the future.
There’s a page on the wiki that lists a few more options, and links to install syntax highlighters for each of them: Development Tools | ChoiceScript Wiki | Fandom
Multireplace is awsome, but what’s this alternative page break you speak of?