AW trans are pretty damn durable. Obviously there are limits, but they are quite a bit higher than a lot of people assume.
You can certainly go higher than Aero spec. To keep it safe you want torque to not be ridiculous, and you'll want it to come on gradually. There are plenty of people out there with 300+ hp on these boxes. I try to a double drain/fill every 2-3 oil changes on my 9-3.
always a SAAB guy at heart