F) While I am at it, does gambit new module system support introspection or reflection?
I don't know about this one, but it's at least possible to find all the symbols accessible in the current environment: https://misc.lassi.io/2019/gambit-apropos.scm
Gambit's R7RS library support is built on top of its native "namespaces" mechanism, so anything that can be done to namespaces should be possible to do to libraries.
The slides from the Modules talk at Gambit@30 are a good intro: https://github.com/gambit/gambit-at-30/blob/master/talks/Gambit30-Modules.pdf. Marc is also updating the module/namespace parts of Gambit's manual in the near future.
Here are the slides for the presentation about Gambit's upcoming Geiser (Emacs) support which relies on reflection a lot: https://github.com/gambit/gambit-at-30/tree/master/talks/gambitWithGeiser