Hi Rich, sorry for the delay in my response. I feel oddly deflated after writing the GMAT last week.

I am GMAT'ed out.
To your questions -
1) How did you score on each of your practice CATs (including the Quant and Verbal Scaled Scores?
Nov 14 - Q44 (second time taking)
Dec 6 - Q45 (second time taking)
Jan 1 - Q40 (was sick this day, first time taking)
Jan 4 - Q48 (first time taking)
There were also some Manhattan tests in between, which I won't post because their experience was radically different from the GMAT and GMATPrep practice tests.
2) Did you take the ENTIRE CAT (including the Essay and IR sections)?
I did on the latter two tests.
3) Did you take them at home?
Yes, where I have a needy cat and there's construction noise.
Perhaps worth mentioning, when I wrote the actual test I wasn't at all comfortable with the giant monitor and giant text... Took until half way through to get used to it. The text was so big I had to read and reread.
4) Did you take them at the same time of day as your Official GMAT?
All of them at 4pm.
5) Did you ever do ANYTHING during your CATs that you couldn't do on Test Day (pause the CAT, skip sections, take longer breaks, etc.)?
I think I paused once when my partner came home and began talking - he didn't realize I was taking a practice exam but then I immediately got back to work. Think that was in December.
6) Did you ever take a CAT more than once?
Yes, but not the latter two.