Aser,
Yes a fuel leak somewhere in the fuselage (look at the routing of the fuel lines to picture how many corners and wire bundles it can wash over as it goes) is a much bigger problem, by far, than an engine flameout in a Cat A twin.
The concept of suction fuel does not automatically mean that any fuel line leak would mean a flameout. The suction level is very low (about 3 psi at the lowest place in the fuel system, about 1 psi at the top) so that a small leak spot would introduce some air, but typically not enough to cause an engine shutdown. S-76 drivers know that the typical sign of a fuel system leak is a blinking fuel pressure light, showing that bubbles are being eaten by the engine. These bubbles are the air that went in, instead of feul pissing out.
The difference between a 1-3 psi suction, and a 10 to 40 psi fuel spray into the fuselage is the point I am making, and it is an important point, important enough that US Mil spec no longer allows pressurized fuel systems.
The benifits are only available if you have no fuel pressure. A design with boost pumps on is not a suction design, and is inherently more fire prone.