I've just "googled" the abbreviation DVE - another new one since I hung up my headset! How degraded must the conditions be they officially become a "degraded visual environment?"
However, to return to the subjects on the thread: my thoughts are, if there is any doubt about "getting in", do a coupled approach. Over the sea, on a "gloupy night" qualifies, in my view, for using all the help you can get. However, if it's a few km of vis and say 500' ceiling on an ILS/localiser approach, why not hand fly whenever the conditions are reasonable.
Otherwise, how DO you keep in practice, either for a proficiency check, where I presume you still need to demonstrate hand-flying ability, or when some or all of the autopilot functions are no longer available? Crab gets it right when he says that flying is a degradable skill - use it or you will lose it!
I appreciate that this sad event off Sumburgh - to judge by the contents of this forum - seems to have been due management of the autopilot functions, rather than manual flying skills. However, it worries me that we may have a generation of pilots who are out of their "comfort zone" when manually flying.