What you're saying is correct, but the second is only approximately a day / (12*60^2). To quote Wikipedia: Since 1967, the second has been defined to be the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. So the second is precisely defined. The length of a "day" however varies. It can vary due to many things including tides nearby astronomical objects and other things. The recent earthquake in Japan shortened the day by 1.8 microseconds. This may not seem like much, but combined with all the other effects and the fact that the astronomical day is not an exact multiple of the second, every few years a "leap second" is added to UTC to match up with what the earth is actually doing. The last leap second was added between 2008 and 2009 (at the end of 31st Dec 2008).

Of course, this is neglecting air-resistance, which I'm not sure is a valid assumption. Nevermind.

It would read 1G after it had hit the ground (stationary lying on the ground), but during the impact, it would be far more than that. It would read 0G during freefall (as this is the definition of freefall). The deceleration as it hits the ground would be very high, (possibly even as much as 100G+) because the time to decelerate is so small, and the distance over which it decelerates is tiny.

That is an excellent poem. Very cleverly written.