about basic operation of guix sd

[Satoru KURASHIKI]

hi,

I happen to know Guix SD recently, and trying to tinkering it.

I've just managed to "guix init" on my new box, and have questions
about its operations.
# excuse: I looked over the guix manual, but may be overlooking clues...

Please tell me any of FAQ, Howto, list thread, blog, sample code, or
gist, which would answer:

- How to unify personal substitutes?
  - "guix publish" will serve the substitutes built on that host, and
I want to add substitutes
    of another host's
  - Is this work as expected? : rsync /gnu/store to repository host to
merge substitutes

- The right way of treating guix code (or guile code structure?)
  - I have to clone guix repo into my home directory?
    - Though "guix pull" should have source tree anywhere (in
/gnu/store?), so are there any interfaces
      to access them through guix-daemon?
  - I want to tweak existing code (package definition)
    - I should copy target file to somewhere working directory to edit
      or edit target file in the project tree？

- Emacs setup (to edit guix configuration)
  - I want something like:
    - i.e. M-x guix-describe-variables to view document of guix
keywords and jump to its definition
    - C-x C-e to evaluate variables (to confirm its values)
    - guix keyword completion
    - Some linter (flymake/flycheck thing)
  - emacs-guix seems to be "guix" command wrapper, so I guess
configuring geiser will make it?

regards,
-- 
KURASHIKI Satoru