Character not pinning or detecting in camera

First, some terminology, a "mesh" is a layer and all its children, until a layer is marked independent. The independent layer starts a new child mesh. If you put a pin on a layer in the root mesh, it will stick that position relative to the scene. E.g. if on the BODY layer for example. But if you put a pin on a nested mesh, such as the legs (because the legs are marked as independent), it will pin the position of the legs relative to the body. So either you need to make the legs not independent, or pin the character on the torso (around the waist somewhere - low on the torso).

For the second point, I assume you mean the new body tracking support? I assume you are standing back a bit from the camera (so it can see most of your body), and that you see the lines on the web cam view? Did you add a "Body" behavior to the root of the puppet? If you look in the properties panel, do you see the Body behavior there? And if you expand Handles, do you see Waist with a count greater than 0, then hips and shoulders with counts greater than zero, and so on? if it misses a handle it needs (e.g. for shoulders), the lower part of the arm won't work. That is, if Left Wrist has a count of zero, then check Left Elbow, and if zero check Left Shoulder,, and so on. The Body behavior is how the puppet gets controlled by the body tracking.