Yeah, macros are advanced and come with a lot of footguns that take years of experience to even realize their existence, especially in Lisp, which has a much more powerful macro system. I will refrain from asking more macro questions until I have had time to see how they map over :)
I see. Also I really like Crystal and I don't mean to sound like a Lisp snob, because there are plenty of them. Lisp is nice, but it's too dynamic for some tasks...which is one thing that makes its macro system powerful. Every phase of the compiler can be invoked by any other phase by the user, which means macros can be expanded at runtime and all that. It's a mind!@#$, really.
I am torn. While I do agree, what has kept Lisp a viable language since the 50's is that new language features and are just a macro away. There's only so much you can do without creating new compiler extensions (macros).