Well, for one thing, it really shortens the discussion if you take advantage of it. For all languages that require arbitrary code execution in that language at compile time in order to be parsed, parsing therefore is Turing complete and therefore has all properties of Turing completeness, including undecidability. QED.

Is it? (I honestly have no idea about Lisp.) It isn't just about being able to do stuff at compile time: In Perl's case, as I understand it, you can't determine if a string of text is a valid (in the sense of generating an AST!) Perl program without executing it. This precludes things like reliable syntax highlighting.

Languages can include meta-programming/macro facilities without effecting whether or not the parser can do its job; I am fairly certain that Rust's macros are an example of this. Python, as a more dynamic language, also includes metaprogramming facilities (metaclasses, decorators) but IIRC, can still be parsed without needing to simulate a Turing machine.

Indeed it's not ready. It loads and reacts to clicks too fast and doesn't use two megabytes of JavaScript.