The extended hanger would seem to have a propensity to have a "lever action" especially when the distal end of the forearm is moved.
You got that right. Most Ruger #1s will not like to shoot off a bipod. They will not like to shoot well off a hard rest. The cantilever rod acts like a launching spring and the rifle barrel will go flying up in the air before the bullet clears. You want to rest the forend on something that absorbs recoil but doesnot reflect it back.
The foreend screw can be used to "tune" the barrel. There are various techniques for building pressure points in the foreend or trying to float the foreend. There is a device known as a Hicks Accuraizer that can be installed with a little woodworking. I have one laying in a drawer but building a pressure point at the end of the foreend works well for me so the Hicks just lays in the drawer unused.
They are enjoyable rifles and are fun to shoot and fun to hunt with. They can be as accurate as any factory rifle around or they can be really a dog. They will have a good bit of "freebore" so you will have trouble reaching the lands with light bullets. Don't let the barrel get hot or it will start walking around pretty bad.