I was wondering if its possible to either set up one queue on a single interface to do both incoming and outgoing traffic?
No, not at present.
Or maybe possibly having it on split interface's but assigned to one queue. eg:
pass out on dc1 from <za> to 196.34.165.210 keep state queue opium_01_l
pass in on fxp0 from <za> to 196.34.165.210 keep state queue opium_01_l
A queue must be tied to an interface; it can't be "floating" for use with any flow. One thing you can do is specify queues with the same name on different interfaces (this ties in with the IN tagging I mentioned in the last thread), but this probably isn't what you're after.
