I think that any place in the world where two or more tectonic plates are applying force on each other, there is a chance for both volcanic action as well as earthquakes.
Indeed. It's been a long time since Geology 101, but essentially many volcanoes form along fault lines as one plate slips below another. The plate going under can build pressure, which when it releases causes earthquakes, and also melt is it goes below, which rises to form a volcano.
If the plates collide and both push upwards then you get non-volcanic mountains, but still the chance at earthquakes. On the flip side, when you have volcanoes not caused by plate tectonics (such as Hawaii, which is simply a "hot spot" over which the crust moves), then you typically get heavy volcanic activity but since there's no faults, there's little chance at an earthquake.
Also, the source of the material being melted will heavily influence the type of eruption. Oceanic crust that melts is very viscous and will more or less just spew out hot lava (like in Hawaii) that is destructive, but with little explosive force.. Continental crust on the other hand tends to explode generating huge ash plumes (a la Mt St Helens).