It is disruptive when more than a few newsgroups receive the message. This way all the messages will go to the most related newsgroup and everyone who is interested knows where to look for it. If the topic is Ontario politics, use ont.general for the daily messages. Monthly you could post a reminder about the discussion in the other groups. Mostly HWCN is self-policing.
All members define what the community standards are with each post on the system.
If you use language that others find offensive, you will hear from users that object. Most HWCN newsgroups do not have any swearing or offensive language but each newsgroup has slightly different ideas about what is okay. You may also find that some newsgroups have agreements about topics which cannot be discussed there. These arguments can't be resolved so a truce may have been declared. Again, read the newsgroup and FAQs to learn what belongs where.