Most people adjust the DIN setting by themselves using a DIN Number Chart or On-line Calculator.
That has to be done, and is fairly simple to do.
A lot of people forget to adjust the foreward pressure. That is a little bit harder to do, and the exact method depends on the particular binding used (e.g. most volkls have a screw that screws into the heel housing and must be flush when the boot is in the binding, Tyrolias have a tab on the bottom that with a scribed range that must align with the heel housing when the boot is in the binding, All have some sort of marker that moves as the boot is clamped down and must be within a specified range).
If you do decide to do it yourself make sure you know how to adjust the forward pressure.
Torque testing verifies that when you set the DIN to the number given by the chart the binding will in fact release at the torque it is supposed to release at. New bindings are seldom off. Old bindings might be off, but you might also want to adjust your DIN setting up or down regardless, so I would not bother with a torque test, but that's just me.
More importantly if the bindings are not on the "indemnified list" the shop won't touch them. That is your clue that more than likely the bindings are too old to be considered safe (there are exceptions, but knowing what they are requires expert knowledge). You could always look up your bindings to see if they are on the current indemnified list.
Depending on how badly your local ski shops want to serve you properly or how badly they want to rip you off, it might be best to have them set the binding and torque test it. Best advice is to phone them and get them to tell you what they would charge for that service. It should not cost more than 20 bucks, imho. The money spent would then be a bargain considering the peace of mind obtained.