Hi,

I was wondering if it's possible to configure a routeros device as a internal router (only one area) for a area that's not area0? If this is not possible that would indicate that all routeros devices would have to function as ABR (since they would be in both the desired area and area0), something I would really like to avoid if possible.

It seems it's not possible to disable / remove the area0. It's possible to change the area on the area named backbone or remove it by first changing the name. However after a reboot the area0 always reappear in ospf area list.

Any help would be most welcome!

Yes it is possible.
If area0 is present in configuration it doesn't men it is active.

For example,
/routing ospf area
add name=area1 area-id=1.1.1.1
/routing ospf network
add network=x.x.x.x/xx area=area1

in this case router is configured to work only with area1