[Focus man. Focus.]

Yes it is a saftey concern for them to refuse the dyno run due to the leaky struts and a broken spring. You need to think that they are running your car a 40kph in a stationary position. If something was to break (not saying that it would) your car, the dyno, the mechanic and the store would be damaged beyond repair. Many places don't check very closely so you will probably find another shop that will do the test for you.

It was not Canadian Tire looking to sell you some un-needed parts.