As explained to me in 747 and DC-8 Schools, the engings are put on pylons on the wings so the wings can be made thinner. (Stopping the upward flexing during flight).
There are fuse bolts that will allow the engine to be slung so as not to rip the wing off in flight during a high g loading.
Many years ago, 737-200's were dropping engines all over the place. While they worked on a fix, a red line was painted on the aft end of the engine mount and engine; if it didn't line up a fuse bolt broke.
Many carriers have slung engines in flight.....I can recall two, one over Denver and one over Anchorage, both in mountain wave turbulence.
I'm not sure why they are mounted forward.....the early jets didn't do that though.....seems to me the closer the thrust line is to the center of gravity the less pitching moment with the application and reduction of power.
Generally, airlines prefer a loading with an aft cg as it burns less fuel.