To use 'remove' you need to import the srfi-1 module indeed.

> guix system: error: service 'ntpd' requires 'networking', which is not
> provided by any service

This is telling you that you can't have the ntpd service if you remove the
network stack, so
- either remove ntpd
- or add another network stack that provides 'networking' (maybe wicd or the
like).

> Also, how to rescue my system when I will not have a possibility to use
> network at all. How then use usb-stick with guixsd and reconfigure my system
> with my previous config?

Is it a hardware / kernel issue?  Or do you mean that network manager will be
gone?

For the latter, iproute2, wpa_supplicant and friends should still be available for
you to connect manually.

When it comes to system rescue, you should be able to boot the former system
generations from the bootloader.  Isn't this working for you?

-- 
Pierre Neidhardt
https://ambrevar.xyz/