Superman

I watched Superman once with my brother and another friend, but then dad wanted to watch it as well, so it was made into a family trip, and i got to watch it for a second time. And as you may have done before, we tend to notice things that we missed the first time around. The report where superman is seen all over the globe, i caught a fleeting mention of "Gotham". While i know that in the DC universe Gotham exists alongside Metropolis (is that his city? nevermind), still, hearing it gave me a tiny thrill.

WARNING, SPOILER ALERT, READ AT YOUR OWN RISK

However, i soon started to notice little physics errors. So, physics buffs! Can any of you help answer these observations?

1) During the scene where Superman was playing omnipresent Ear-In-The-Sky, he hears the gatling gun thief and swoops down with a sonic boom. The thing is, we hear the boom instantaneously, as he hits atmosphere. While he could be travelling fast enough to break the sound barrier as soon as he hits thick air, should we hear it a few seconds after he passes through? From our vantage point. =/

2) You know how Kitty "accidentally" dropped the crystals from the plane? and on the spot of ground where the helicopter is, where the crystals dropped, it collapsed. So didn't the crystals fall into the sea? Why didn't they sprout and grow?

3) Superman lifts the entire crystal continent off into orbit, and with a final push, the continent sails off into space. Then, weakened, he slowly drifts back into the atmos- but wait! he is extremely close proximity with a landmass the size of a largish island, and at that height, even a mass the size of a large island isn't sufficiently attracted by the earths gravity anymore. So why should Superman be attracted to the earth? He is in such close proximity with the landmass, he should be pulled by its gravity field instead, shouldn't he?

4) After he ejects the island inland into space, he falls back, cape flutteri- wait, how come his cape flutters? At the distance where an island can be released into space, there should be no more air! =/

Anyway, i am a bio-person, not a physics person. Perhaps i am just misguided and mistaken. If so, please correct me =P

I am, however, happy that the director thought of a freefall situation in the plane, when it was falling, in the very beginning. Yay for freefalling. So.. thats about it. Please tell me if you people see anything else in the movie worth mentioning.