You should be able to ignore people in the forum and PM's, though I haven't created an alt account and tested it. There is no ignore "button" in the forum but here's how to add people to your ignore list, should they be pestering you in one way or another:
1. Click on the profile tab at the top.
2. Hover over "modify profile" and select "buddies/ignore list
3. Add/take people off your ignore list.
