Our instance is at `http://ourwiki/questions`. We'd like it to be (and we'd set up and dns alias/reverse proxy) `http://q`.
We could change the dns alias/reverse proxy to achieve this, but I'm guessing Questions would still write out links etc. as `http://ourwiki\questions`.
Is there a way to configure this?
You're right that Confluence is going to write links based on the base URL of the system, and that it's going to use /questions as the path for Confluence Questions. There's not a way to change this path via configuration option. If you were super determined, you might be able to modify some files in the Confluence install directory to get that path to change. I'd not recommend going that path though as it's extremely difficult to get _all_ the right changes made for modifications like that without breaking the application. You'd also risk breaking any future upgrades you need to do as any modifications you make would need to be manually re-applied after an upgrade.
I like that you've looked at and maybe set up some DNS shortcuts already - they're super handy! Doing them by hand is fun but I'd also recommend having a look at some URL shortening / DNS shortcut services you can run on your own infrastructure. This article is written by a company that offers this service but lays out a pretty good history of these types of services (Go Links) and some open source projects you can deploy.