The Focus spent a week in the shop...
...and it appears they got it right this time.
I had two issues:
-the jerky/juddery/harsh clutch engagement, with odd traction control involvement that either contributed to the juddering or sometimes cut the power altogether; I had been complaining about all this for months, and it had already spent time in the shop; the problem continued to get worse, and was coupled with computer/gear selection issues
-steering wheel controls issues; cruise, infotainment, etc either wouldn't work or worked oddly or intermittently.
The fixes included replacing the clutches in the tranny and the clockspring in the steering column. Both seem to have done the job; the transmission now engages smoothly (as did the tranny in the 8K SE loaner I had for a week), and usually selects an appropriate gear. The steering wheel controls now seem to work all the time.
So we shall see; I've had enough trouble to make me a little hesitant about the car, but I'm hoping happier days are here.
So a belated 'thank-you' to Ford Customer Service and my local Ford garage; a belated thank-you because it took 'em awhile to fix it; I'm pleased all the same.