Iran wouldn't have touched Tim since he is a UK citizen. That is just begging for the US to go 'special relatioship' on his ass. Linus is a finn, so he is properly also safe. I don't know the last one.

They were touching those American hikers for a couple years though, weren't they?

In that case, it was clear that the Americans committed some sort of crime (straying across an international border), and so it was Iran's right to do whatever they wanted (to extract as much political value from the event as possible).

Someone visiting the country on a valid visa and facing execution because of their positive contributions to society in their home country is a whole other issue. I'm guessing that Iran, in that case, would have a lot less precedent to stand on, so they might not play the same political games.