So is it a statement of fact or one of opinion to be called a jerk? American Heritage Dictionary defines a 'jerk' as 'a foolish, rude, or contemptible person.'
The statement is one of opinion. Therefore, the use of such a term should not be punished as libel or slander.
Precisely because the bounds of the terms "foolish" and "contemptible" are so vague, using the term does not amount to making a statement of fact. The words inherently carry value judgments. On the other hand, saying "A killed B" or "X has AIDS" are clearly statements of fact rather than statements of opinion.
The word "outrageous" is inherently subjective. It does not necessarily correspond to any particular chemical pattern. Sure, you might believe that if an action gives rise to a particular chemical pattern, then it is outrageous, but that's just your definition of "outrageous"--there is no reason to believe that your definition is in any sense "correct."
It's not that it's solemn; it's that it's a private event being crashed and ruined by these people. What gives them the right to do that?
Obviously, if the Westboro Baptists were to trespass on private property, they would be guilty of a crime and a tort, and could be punished for doing so both criminally and civilly. However, just because individuals wish to participate in a "private event" on public property (such as a road), it does not follow that they have the right to exclude other people from that property.