With the gracious and patient help of Brian Ingerson, I've got up and running a Kwiki as a CMS for managing documents in and about the Haida language! As to the customizations: most were straightforward; but for example, you don't need codeblocks in this system, but you do need little wordlist-like annotations of passages here and there, so we overrode the Kwiki code that makes indented regions into codeblocks, and made them instead become something sort of halfway between HTML "blockquote" and "pre".
Ingy seemed eager to help, partly because he's just a really nice guy, and partly because I think I was trying to make Kwiki do something no-one had ever wanted it to do, so that this was apparently an interesting test of the configurability of the system. It seems to work great! I'll have to release it no CPAN as a Kwiki-tweak example, once I've tested it a bit.