1. That is not a really bad idea, since it might sometimes be clashes betweem where something links, and for instance the username "grep". Otherwise, a simple [grep] is enough to link to the site docs. (Using [syntax://] or perhaps [doc://] could provide a way to show exactly what you want to link to. The site docs are of course outdated, but links onward to other resources in a very elegant way (++ whoever fixed that).

2. As you can see at What shortcuts can I use for linking to other information?, most link types link offsite, to useful places like Google and CPAN. This is a good thing, as it provides easy ways to link to extra information, without needing to have it all on this very site (imagine mirroring all of google just because you don't want to link offsite).

I have never heard of anyone having any trouble with any disjointed experience due to offsite linking, that is a big part of how the internet works after all, with cross-referencing and links to places of information.

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It is pitch black. You are likely to be eaten by a grue.