I think some of you are missing the point of the MTO Safety Certification.
The safety cert is not intended to protect the buyer from purchasing a crappy bike, it's to protect everyone else on the road. So the safety cert ensures that the headlights, turn signals, brake lights work, so others can see you and know what you are going to do. It makes sure that the bike will stop when you pull the brake lever so you don't run into anyone else. It makes sure you won't leave a trail of motorcycle parts behind you on the road that will cause an accident.
The safety certification will not check if the valves are leaky or the oil hasn't been changed in years. It won't show if your blinker fluid needs to be topped up. That's not the point of the safety cert.
So yes, bring it into your mechanic to get it looked over to check for all of the above. But you're not doing that for the safety cert anymore. That's a more comprehensive inspection that's got nothing to do with a safety cert.
The point is: You get the safety cert to get the government off your back so you can register it without any hassle. I wouldn't care who performed it. Your mechanic, my mechanic, Canadian Tire, who cares? Just get that piece of paper signed and then do your own due diligence to determine whether the bike is mechanically and cosmetically up to your own standards above and beyond the very narrow MTO Safety Cert guidelines.