It's terrible for it but I think you could keep driving it. Our motor ran out of oil and the injectors kept working. Also why have you not fixed the oil leak before parking it on your driveway and dumping a bunch of oil in it?
Yes, for the 1993.5 and up 7.3L HEUI engines, though by the time that happens you have already damaged the engine, it just will not be a catastrophic failure with rods exiting the block or oil pan.i read that the injectors will quit working when the oil gets low