You can keep driving the car without any hazard, but don't wait too long before you're going to repair it. The smell of diesel will be coming into your car for several weeks after you have had a serious diesel leak.
Changing the injector return hoses is something you can do yourself.
Congratulations with the new vehicle! If this is the only problem that you are going to face, it will be all right.
with a minor 600+k