I have read all (I think) of this thread and note that one or two have posted that the RR and EA engines are interchangable. I find this very hard to believe.
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My understanding is that the 787 and its engines/pylons are the first to be designed to permit engine interchangeability. Therefore, I doubt that is the case on the A380.
Iro insurance/damages, I'd be very surprised if the warranty and liability conditions attached to the supply of the engines, and the airframe come to that, leave RR exposed to consequential losses beyond the replacement of the engines. However, under TotalCare there may be further obigations to guarantee the availability of serviceable engines but I would have thought that even under this agreement RR's liabilities will still be limited.