Hi Aaron, when I first started installing metal switches I was petrified about wires coming loose etc. However I am now on my tenth rewire and every house has metal switches, sockets, isolators, spurs etc etc so I had to get over it.
You would have to be extremly unlucky for someone to get badly hurt by way of a loose wire. Firstly if a good earth goes to the switch you have one form of cover, secondly are the lights covered by RCD? If so they will trip out at 30mA in 30 Ms ( or 40mA in 40Ms) which again would prevent harm. Thirdly if you look closely you should see that the switch is actually protected from the metal plate by plastic, this prevents peoples fingers coming into direct contact.
As long as you take good care in terminating the wires inside the switch you should have no problems, make sure the screw is nipped up nice but don't overtighten as this can fracture the core.
You say that you have only been doing this for 2 months? Are you working for someone? If so get them to check it for you for peace of mind.