Is there any way, in C7, to select multiple tracks at the same time and add a track icon/picture to all of them in the one go?
i dont think there is such a thing.
there were some good suggestions for handling and assigning track pictures faster and in more convenient way in FR forum (they are buried somewhere there 
)
like adding bunch of same picture tracks at ones, searching pic name by text input,filter pic names by track name automaticly, having pic settings (color intensity etc… ) fixed until changing it.
hope steinberg improve picture track section in next cubase updates, now it takes too much time assigning pics to each track.
i dont even bother to assign pic track now. 