My new layout is not going to be a roundy-roundy but a dogbone. It will probably have 3 terminal stations that attach to both tracks. The one that's in now has a double junction (with additional double slip switch!). I plan to make the exit track an X-section, picking up feed from either the mainline or the station track as required.
Now, is there any better way to do this? It looks as if exiting trains will have to stop on the mainline while I change the switch back and then change the direction switch.
Is there a good way to wire a dogbone so that its clear what is happening with the direction controls?
And should I abandon the common-rail wiring?

Without seeing a track plan with gaps, it's a little hard to give the best answers. The one thing you almost certainly need to do is abandon common rail wiring, since the reversing section needs to have both rails isolated. My experience has been that common rail wiring adds to the mental effort you need to do to wire the layout anyhow.

I agree with JWB...Need a trackplan...And common rail wiring can't be used for the reason he states...