CSENG
We fly manually all the time. FDB are not an automated airline. Hand flying is encouraged and practiced as often as viable. We use the autopilot in the cruise and that is pretty much it. for everyday. Some guys put the autopilot in at 1000ft after take off, some wait until flaps up no lights, some hand fly up to FL410. (If were not too heavy or first cruise ALT)
We frequently hand fly from well above platform to touchdown.
Whenever in the NG you disconnect the autopilot you disconnect the auto throttle. It was something that I had to unlearn when I did my 777/787 type rating as in that aircraft you never (I'll put very rarely as a caveat) disconnect the authothrottle.
The only time in an NG that you fly mixed auto manual is if you disconnect the AP, then deselect the auto throttle but not disconnect it. This is known as deselecting speed and is something I have down, AS SOP, in other airlines but something that FDB DO NOT DO. (for the avoidance of doubt)
So in FDB it was simple if you disconnect the AP then the AT comes out as well. As there are no automatic approaches flown most of the above conversation about modes and trim bias etc are simply not relevant in this or any other FDB case.