Yes, and rotate it.
If you mean the pivot angle of the trailing arm relative to the torsion bar, IIRC 9°.
Yup. Swing axle offroad cars are pretty much limited to about 8" of working travel. SCORE Class 9 buggy rules requires swingaxle rear suspension with stock transaxle. SCORE Class 11 requires swingaxle for cars that start out as swingaxle. Such as 1968 or earlier models. Check out YouTube videos of both classes of race cars. You'll find they offroad pretty damned well. Unlimited classes of offroad race cars used swingaxle for decades. In the early days of the Baja 1000, 6" of travel was the norm. My Baja has about 9" of rear travel. It gets driven VERY hard offroad. More travel is nice, but NOT absolutely necessary.
Hot rodders have an old saying that my dad taught me. I've adjusted it slightly based on personal observations.
"Speed costs money, how fast can you afford to go?"
I further modify it based on many decades of offroad experience.
"Wheel travel costs money, how much travel can you afford?"
For $300-600,000 you can have a new trophy truck with about 30" of wheel travel all around.