Merging changes is hard to implement in a user-friendly way.
Here are some potential design ideas...
webservices interface to corporate confluence, secured with standard ssl/tls, open to the internet, either the same authentication as the internal system or digital certificate based, issued by a confluence plugin, signed by a confluence root cert.
a local 'confluence light' server on your laptop, all java, mac or windows or linux.
It is configured to connect to a parent (the internal corporate confluence) installation via webservices, authenticate itself, and receive its configuration information this way.
Users can mark any page or hierarchy as "keep in sync with my local one." The next time your local install connects to the parent, it gets a list of pages and sucks down, throttled, what its supposed to.
"local" copies can be viewed and edited "offline" but as soon as a network connection is available, the local confluence tries to reach the parent and if so, checks versions of the pages marked for sync and if its local ones are only 1 version higher than the parents', there's no conflict, it uploads the changes. The idea being people are rarely offline for 6 weeks, but offline for 3 hours, then online for 30 minutes, then offline for 5 hours, then online for an hour, etc. and during those online times, changes could be synced more often to prevent merge headaches. If there's a conflict, resolution as simple as replace it or dont replace it, basically totally manual, would be ok with me.
Just some ideas...