under charging and OVER charging. There's many hosts that do things as an included service, such as script installations etc, and for some they offer an install fee for certain things (which is fine) but when they try to gouge someone for services, that gets a little nit-picky to the user. A prime example is SSL Installs. If you use cPanel, there's an installation button in the control panel. We've seen web hosts that charge $30 if a user doesn't run the install themselves and wants the host to do it. I've no problem with someone charging, but $30 and more? Seems a little high.
The other item that we see that causes hosts problems is discussion of clients on forums. Users and clients read forums and search google etc. The last thing they want to see is you (the host) bashing them, their business, or how stupid you think they may be. This is something that we see many smaller hosts do when they're starting out and getting frustrated. All I can say is don't do it. It'll live in google forever and come back to bite you in the end.