Evaluating possible early breaker failures
If you've had some trouble, you're certainly not being paranoid.  

I am curious why the service person didn't move the circuit to a fresh breaker in a fresh spot in the panel, I wonder if the contact surfaces from the bad breaker are messed up, they may need attention.  I also feel it's best to take questionable equipment completely out of service, I wouldn't have put it in a fresh spot in the panel.  It's possible this problem may be beyond the service person's electrical expertise, some maintenance people are fully qualified licensed electricians, some know just enough to be dangerous (literally).  

I never like to switch lights at the panel.  Like everything else, breaker quality isn't what it used to be.  There's usually a better way to do things without breaking the bank.  

Anyway, I bet you already thought of all of the above.  I'd suggest you have the panel inspected by a qualified commercial electrician who will have the knowledge and equipment to conclusively test the breaker.  If they find no trouble then you spent a few bucks to rest easy, if they find trouble it would be reasonable to ask the landlord to reimburse you for the cost of the testing.