Hi Richard,
>> rji.timepeace.co.nz - and this is secure, (using Ports 443 and 80 in the settings)
good. This is all right.
Now let's say you want another server on the same server. You have some choices;
a) run both servers under the multi-site host program. They can then share ports 80 and 443. You would then get a second sub-domain name to differentiate them eg rji.timepeace.co.nz and admin.timepeace.co.nz
OR
b) run the first server under port 80/443. run the second server using a different port (insecure port remains 0, so for example 0/4430)
then you access the second server using rji.timepeace.co.nz:4430
>> sharing the same web folder, certificate folder, and data files
the apps would not need to share the web folder, or data files, but the second app should use the shared certificate folder as you are doing. So the second app doesn't care about the certificates - the first app will take care of that.
cheers
Bruce