I think the important bit is to not throw that information away until after you've reported any compile errors. Once you know the code is valid, you can discard that stuff (unless you need it to generate debugging information).

Oh, yes, that's fine. Although by that point you've kind of already spent the time, so it's not going to gain you much by throwing it out.

Because your error messages might be less-than-useful. Not that Wasabi ever had an issue with that. Cough.