Well, day 3 of this install has bought success for the most part.
NetZ is right, there is no status output which could be used on the Omega Rallystarter. I did decide to use a relay with the following setup:
Pin 30 - Ground
Pin 85 - Starter Wire off remote pack
Pin 86- Ground
Pin 87 - Non-Ground side of clutch
IGN1, IGN2 both provide 12 volts positive all the time while the remote start is on and when the car is started normally, using either would result in a permanent bypass while the car is running as far as I can tell.
The current setup works great and bypasses the clutch when the remote start is initiated and the car started.
HOWEVER...... this also bypasses the clutch when starting the car with the key, as the same starter wire passes positive voltage when using the key, which makes sense.
I do have the neutral sense working, which is good, I did try to tie the parking brake (light green wire) into the clutch bypass relay.
This didn't work, it seems my parking brake provides enough of a ground (whether up or down) that the clutch bypass relay still has the 2 grounds needed.
So, overall, it integrates with the OEM alarm very well, however the Omega Rallystarter seems to limit your options on a manual transmission (Status ouput, parking brake line in etc etc). I did have to use another relay to convert the door lock pulse into a ground to trigger the remote start activation. So 2 relays later, the Omega Rallystarter is not plug and play for WRX's or STi's.
Any thoughts on the best way to use the ground signal of the parking brake (while engaged) as I would like to have two points of failure, the neutral sense and then a parking brake check before this thing starts.