I'm totally fine with #2, if you do have a good separate compilation unit story. I'm fact, it's how many lisps work, and it works out quite well.

However, I wasn't talking just about your compile time asserts for #1. There's also syntax errors, undefined identifiers, missing or extra arguments, etc, etc. That stuff is hard to get right if you want to report many independent errors. It gets much easier if you can change your language, so don't wait too long to take a swing at it.