From what I understand, most Joomla 3.x components now have a helper file called route.php which I think is related to SEF.

This is a required file (I think) for a search plugin, which I am currently trying to write.

Should components generated by Cook have this file now as a helper?

On another note, has anyone written a search plugin for a J3 component constructed by Cook who would be willing to share their code?

Yes you have it already, it is called router.php (Front side)

Oh my word... I could not see it for looking..

Can it be called as a helper in a search plugin?

I don't know.

Why not ?
Instance the class alone and use it.