yes
Since the government won't admit there are UFOs they most certainly won't admit to reverse technology stemming from UFOs. So the answer is we just don't know. But some ideas have been guessed at, from lasers to anti-gravity propulsion.
No. The horse has been selectively bred.
Yes. Well, at least assuming I understand you question. If by "engineered" you mean that it was though out to work according to the laws of physics, then yes. Every building since the Renaissance (and many before) has been "engineered". Maybe a peasant hovel might no have been, but even your house was most likely "engineered".
Cancer
you
Not at all. There are many foods that you eat that have been genetically engineered to produce something better or faster than before.
contrivances
Yes, there are few instances where cases have been reversed due to suspicion of DNA contamination,Pharmacia Biotech, Milwaukee, WI case reversed due to DNA contamination of the samples.
Three foods that have been genetically engineered are corn, soy, and canola. It is possible that some fruits and vegetables have been genetically engineered using a slightly different method than ones we hear about.
Genetically engineered organisms. Bacteria, yeasts, spiders, goats, etc. have been genetically engineered to mass produce several proteins of medical interest.
difference between engineered fill and non engineered fill material