These are common sense recommendations but should be applied to your specific needs and goals. It also required you to ensure that the appropriate amount of time will be spend from a community management perspective making sure content & comments are within the guidelines – you have to maintain the community integrity.
That being said, posting the ‘playground rules’ helps the community grow and you should find that you are still spending the majority of time encouraging people to participate than trying to keep on top of the bullies. Even to the point of creating some engagement guidelines internally for your organization to help people understand how to engage on the community. Its a lot easier to tell people what not to do but much better to encourage people to do things that drive the community forward even if it takes a bit more effort.