Hahaha! Beeston, this is the right place. The reason some words change automatically is because of spammers or trolls in the past who have ruined it for everyone else. N!ke is a good example. It can be frustrating but it's just something we all have to live with to decrease spam and trolls. If there's a particular word that's causing problems for you, PM a mod and they can give you a more detailed explanation of why it's not able to be posted.

It's an automatic system, mods aren't going in and editing posts.

Good question, hope this clears it up for you and anyone else who was curious.