First, you can change or add anything. But there exist a fair number of people who will delete your changes if they do not conform to the rules.
Second, the group rules. The group meaning the current batch of Wiki active participants. This means community expectations can and do change, so go with the flow.
Third, as Wiki is a community you will find lots of contradictions (rough consensus and outdated pages). So all advice, including this page, is not without people who take exception to information within. A suggestion is to accommodate opposing views, sometimes these are kept in separate pages and linked together.
Fourth, make sure you arm yourself with the knowledge on how to undo the deletes if necessary. There are still people knowledgeable in Wiki matters to help you in a positive manner. Newbies are advised to stay out of conflicts, and accept the fact that they can get caught in unfortunate cross-fires, just like in a real-life night out at the local pub.
Fifth. Once in a great while there is about of impersonation and use of sock puppet's. And the identification of people making changes or distortion of existing material sometimes only serves to mislead. At other times, things can get confusing that even veterans here can mis-interpret both the message and its context.
Sixth. All is not lost. The concept is reasonable. And there is even sometimes good advice from controversial figures. An example I got from one such person being: if you see something good, copy it somewhere off the net, since it may not last till your next visit.
Seventh. Have a "better" life. Get off Wiki to do something that keeps your family happy. But do come back.