rpo, nothing personal but your last post has figit room all in it. You're being somewhat vague and it does not help to fix your problem. What EXACT BRAND are your 'dealer' parts? If not FORD specifically, well, there is part if not all of your problem.
I like much cheaper parts that what Mr. Ford sells too, but in the case of engine and transmission mounts for Focus cars that is almost always a mistake.
To someone earlier, the torque converter clutch cannot partially release to cause vibration unless it is affecting idle speed, the idle will appear to fluctuate more. Car will also have a tendency to try to die or die outright right at the slowest speed point of the braking since dragging converter will drag motor speed down to try to die. If motor idling clean as far as speed there then not converter. Generally the hydraulic issue that causes converter clutch dragging goes pretty much the other way from intended, it would be odd indeed to have the clutch pressure modulated so perfectly that the clutch barely kisses the friction surface to simply vibrate but not pull idle down to die.
Low idle speed can easily be slightly clogged PCV or aircrack at throttle blade too.
Oh, uh, happy Thanksgiving y'all....................