Since these are non-fatal deprecation warnings you should probably just 
ignore them.
Otherwise you would need to fix the sources to use _DEFAULT_SOURCE instead 
of _BSD_SOURCE or _SVID_SOURCE.

Void uses "more" as a sensible default pager, but if you want to use 
another you are of course free to set it to whatever you want. "less" ist 
not neccessarily what everyone wants so it is better to use a well-known 
and small default that can be easily replaced.

You are right about the hostname. I think it would be reasonable to 
automatically add it to /etc/hosts during installation. Then again it's not 
terribly difficult to add it yourself :)