Using wikis to manage a small team's internal documentation and shit is a PITA, particularly because you get into a situation where you need to sort of replicate some formatting on a bunch of different pages but then, whoops, nobody knows how to use the template system in a sane way.
Live preview and some sort of not-shit WYSIWYG would make wikis for small teams much nicer. Then what'd make it even super nicer is lightweight macros and pre-made templates that could be stored in a per-user or per-category way. Like... github, but for wiki-stuff.
First time I ever heard something positive about confluence. (But I only heard about it, because we use it at work and people like to complain about it.)
To me its waaaay better than Sharepoint - which we also used. And it is way more suitable for "non-technical" and "non-wikisavvy" users than e.g. MediaWiki.
I have never used Sharepoint. Fortunately I do not work in a Microsoft shop. (Though we do have to bear Exchange Server.)
One minor misgiving about Confluence is its syntax: Opening and closing tags look the same. So {noformat} both starts and ends its environment. I haven't done anything fancy myself with Confluence, so I can't comment on the other complaints. (And we do use an ancient version, because we have some custom changes, and nobody has found the time to port them to the new version.)
FWIW, I don't really like confluence either (I do have an high opinion of other atlassian's products though), it just seems to fit the OP's wanted-list :)
Live preview and some sort of not-shit WYSIWYG would make wikis for small teams much nicer. Then what'd make it even super nicer is lightweight macros and pre-made templates that could be stored in a per-user or per-category way. Like... github, but for wiki-stuff.