I too do not see the advice in this article.  Why would you want you child to not act silly?  That is apart of growing up.  Even as adults it's still fun to act silly and play around of course if this is an ongoing issue then a behaviour plan needs to be put in place. 

Sorry but I don't really see any advice in this other than to put kids displaying what you call "abnormal" behaviour on a behaviour plan. I don't consider imaginative play abnormal. I'd say school aged children often have wild imaginations and this should be supported and nurtured.

School aged children try to find their place with their peers. This sounds rather innocent - He seems to have found that his peers think he is funny so has adapted to trying to be a class-clown. It's human nature to try to fit in and to be accepted by others. Sometimes these behaviours are harmless and other times the behaviour can be over-the-top.

I can't seem to figure out whether you support government behaviour plans or oppose them?

Kids act silly for no reason, especially if they get a positive response from it and sometimes they just want to be silly.  I think as adults, we expect silliness from our kids but as they grow up, we extinquish the silliness a little at a time until there is no more. It's sad really.

My husband and I encourage silliness with our kids. My son (4 1/2) loves saying that we are a silly family.