Ok, it looks like that fixed it, although I had to use setFocusableInTouchMode. What exactly is the difference between setFocusableInTouchMode and setFocusable? Does it apply to devices with hardware keyboards vs. touchscreen only?
setFocusable worked to disable the focus on the control that prevented the keyboard from giving it focus and most likely the other thread's TabHost focus problem too (untested). Setting it and enabled back to true though didn't get the control full functional again- tapping gave focus then took it away and the keyboard next still skipped it.
Using setFocusableInTouchMode instead toggled it exactly how expected. May want to test it on a device with a hardware keyboard though since it appears that there are 2 focusable toggles- one for keyboard and one for touch. setFocusable appears to turn off both, but only turns on one. setFocusableInTouchMode appears to turn off at least one and turns on the one needed for my device. Doesn't seem to hurt to use both too.