When I join same contacts to one metacontact, it converts to group, but order of contacts in it is not predictable. How I can manually change the order of contacts in metacontact? Or maybe set priority, which contact will be used first if all is online.

Is there any way to do this, maybe via some direct editing of config files?

It's not possible at the moment, sorry.

But it's planned

It's good that this is planned, I ready to wait for new versions! Now I use ubuntu ppa repository with daily git builds, so I can help with testing before release.