Mike,
Sorry for the delay in responding...I have been really busy.
Anyways, to answer your questions...
You are correct, the 1x icon is not getting pushed off of the screen.
In fact, while I was driving home this evening, I actually saw the 1x icon disappear and reappear on it's own when I had EH, and 3G, in addition to when I was pulling 4G...
Also, I am not running any sort of Task Killer, nor any memory management apps. I am not even running any power management app, other than the stock Power Saver options that comes with the stock HTC Sense ROM.
Lastly, no, I did not see the 1x icon disappear before the update to 4.3
Even though I do not have a lot of technical information, it seems that the Power Saver might be actually shutting off the 1x antenna at times.
Otherwise, I have no clue.