I'd have thought it pretty obvious that a big turbopump or combustion chamber failure is going to have an explosive and shrapnel effect likely to take out surrounding engines, similar to the damage we all know a burst turbine wheel can do to an aircraft structure, but there no LOX or methane under monstrous pressure is present to exacerbate the damage.
I thought the flip manoeuvre to be pretty dynamic and wonder at the (immense) additional gyroscopic forces on turbopump components rotating at humongous RPMs. Who knows? But I bet SpaceX does, or soon will and a fix will be forthcoming. It's a completely, radically new engine so of course it'll have teething troubles.
I can't imagine how anyone imagine's they recover booster's and starships from the ocean as they always explode upon arrival; as for "doco's" (sic) I don't think SpaceX is in the business of being very open about operational details, indeed I feel we are only fed highly controlled, trivialised and sanitised info, a distinct contrast to previous generations' coverage on Apollo, Gemini and Mercury missions.
An engine bell that's hit the water is most unlikely to be in a state to be re-used for owt but a planter or conversation piece.
Not at all sure what Ver's refers to?