Inception Question

So, when I was watching the movie, fantastic as it was, I noticed a few holes:

Why, if there's no gravity in the hotel because of the free fall in the van, does the snow fortress not have the same effect?

Does Cob. Actually spin the tip in Youduf's basement? I missed it.

And doe anyone have definitive evidence as to whether it stiopped spinning or not?

528=Perceived [Musical pitch "MI"]
???=Digit space paradox 37
491=Point of reference[Tuning fork pitch]
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Solfeggio frequencies:
    01 = 174 Hz
    02 = 285 Hz
    Ut = 396 Hz
    Re = 417 Hz
    Mi = 528 Hz
    Fa = 639 Hz
    Sol = 741 Hz
    La = 852 Hz
    09 = 963 Hz