1.) It is not required to have someone test your pattern. Most people decide to have testers so they can ensure clarity and ease of their pattern instructions.
2.) (I cannot answer regarding copyright. I leave that to someone else.)
3.) Currently, the only way to do so is to set the cost high enough to discourage international shipping.
4.) Makes are only available for patterns currently on Ribblr.
A lot of info regarding makes is in this thread: