Picky, just to make it clear to all, everything after "excessively long post" is taken from the sci.space.shuttle newsgroup. The info was put together in something of a hurry, while trying to fend off hundreds of newbies asking why the Shuttle didn't just go back to the ISS...
Your first quote is altitude in feet followed by distance from landing. The second one does need fixing.
Aardvark, I'm afraid I don't quite get your point. I think we can take it that acceleration here is measured with respect to the inertial frame of reference of the shuttle itself. It starts at zero, in orbit, and increases during re-entry. My reading of the text is that it is held to about one G. Typical maximum G is 1.6. (For Soyuz craft it is 4-5G, if not more).