3-engine ferry RJ
Regards 3-engine ferries, I have done a 3-engine ferry on a 146. Simple as pie, with an empty aircraft. But the engine has to be secured, to prevent rotation. You roll with two symmetric engines, and then bring in the third after 80 knots.
This A380 would need a thorough inspection, but no reason it cannot do a 3-engine ferry with just a bare pilon and no engine. As long as all the ancillaries are secured, it would be easier without the engine than with. One of the prime reasons for the fat cowling on jets, is to reduce drag after an engine fails. Having no cowl would increase drag beyond the 3-engine ferry certification data.
Silver