1. Yes, you can, just use the joint tool. Click the wrist joint first, then draw the joint. For the next one, just hit 'y' and repeat. Not sure what you mean by "paste" but it doesn't sound like a good idea.
2. Try going Show > All in the Panel menu. They might be turned off. Regardless, it's generally a good idea to draw joints in ortho views and then adjust in perspective, cause it's hard to control where a joint is being placed in persp
3. Use the connect joint tool. Select the joint to be connected by its root, and then the joint to connect to (spine or whatever) and Skeleton > Connect Joint. You might have to change the tool settings to the other option.
Hope that helps