How aeroplane land on specific site however earth is rotating at 1675km/hr ?

I recently browsed a forum where this was debated by the FE believers vs normal OE people. (Obloid Earth).
The FE'ers simply believe that photos, videos etc are hoaxes. :))

A true helicopter is one of the more complex flying machines, pound for pound, that there is. And it is much more difficult to fly than a conventional fixed wing aircraft (about six times the workload for the pilot). Having said that, I am going to assume that you are thinking along the lines of "Hey, wouldn't it be great to put some parts together and have my own little helicopter for flying around." And yes, it would.

Specifically, most folks putting together a homebuilt aircraft or helicopter based around an automotive engine seem to like the engines in Subaru Jettas and the like. However, if you can get something like an IO-360 from Lycoming or TCM (perhaps surplus, parted our from an old airplane), that will produce more power per pound. But I warn you, a helicopter takes a LOT more than just hooking an engine to a rotor.

Probably a lot more practical - look into some of the ultralights. If you really want a helicopter-like vehicle, consider a gyrocopter. A heck of a lot simpler to build. With an "pre-rotate" feature, they can almost take off from a standing start, and have a very short landing roll. Look into a magazine called "Kitplane" for some ideas, and join EAA (Experimental Aircraft Association). Good luck, and fly safe.

You're stuck with a water landing (ditching). Hopefully at altitude the pilot can see a ship and make the landing in the vicinity of the ship for quick rescue. It so rare for a plane to lose power to all engines though that you should never hear of such an incident. Depending on the route, however, Bermuda may be within gliding distance.

Pilot can do anything he judges best for his flight.

In an airliner you are often cruising at 580 knots at about 35000 feet. When you look out at this altitude you are seeing (let's say) 40 miles so a car, if you can pick it out, moving at 70 mph in a 40 mile field of view isn't going to look like it's moving fast at all. By the time it has driven one mile you've flown about 12 miles and probably lost sight of the car.

because if you eject up you will get chopped up in the rotors. it is safer to autorotate and land the helicopter. if you land hard, all the parts that fall off are thrown away from you.

That would be the ground prox system on the aircraft it lets the flight crew know how far they are above the ground during an approach to the landing runway.