I would imagine hitting the engine is probably the safest thing that could happen. The engines are made of titanium alloys and designed to not fail catastrophically. The rest of the aircraft is made of soft materials by comparison.
The aircraft operator will be looking for someone to stick with the repair bill. Each engine on the A-380 today costs about $13 million.
That's the good case. Here's a picture of an A-6E which crashed after an engine ingested a pencil-sized hex wrench.[1]
Not particularly relevant.
J52 engines weren't tested or certificated for bird-strike tolerance or turbine-blade containment.
The later civil derivative, the JT8D, shared a core but was a new design outside the hot-section and had to meet all the FAA-mandated requirements.