Arfur Dent I obviously, as a mere mortal PPL, salute your credentials flying thoroughbreds in the RAF and heavies in Civvy Street but really, I think your prejudice against SEP operations flies in the face of facts (pun kind of intended but excuse it anyway!). If you apply this logic, I hope to goodness you don't drive your single engined car on unlit roads at night? Do you endlessly fear an engine failure in the car (more to go wrong)? I am constantly amazed at the irrational fear expressed by professional pilots that PPLs flying in IMC or at night in SEPs are mad and that they think almost all operations over water are foolish. The facts suggest otherwise.
If, as you will surely know, proper preparation and risk mitigations are taken, the risks are very small indeed. Yes, the fan may quit, and you need to know how to handle that. But it probably won't.
I've had electrical failures, DI failures, comms failures and all sorts. (first 2 over water, 3rd in IMC in icing.... exciting) but happily the training and refresher training and practice kicked in.