no dude. tempo and pitch are identical concepts at different time scales, and the relation of frequency to chroma is exponential. each note is arrived at by multiplying the frequency of the previous note by the twelfth root of 2. obviously, using base 2, we get a natural convergence to a nice "round" number of 2 for an octave made of twelve steps. but you can't just mark two points at 0 and 2, and draw a straight line between them. the graph actually starts out shallow, and grows steeper towards the right.

a sampler speeds loops up and down by the same rules that it speeds sampled instrument hits up and down. there is now way it can tell the difference. it's all just a bunch of samples to it.

look at the frets on a guitar if you don't believe me. the 5th fret is exactly half way between the nut and the 12th, which it would not be according to your math.