I think the points to take away from this very good thread are:-
1) Assess on the ground the weather conditions to see if you can fly your flight in your single engine (for example) safely should an engine fail at certain points along the route. If a point on the route whereby should the engine fail you'd be rowing hard to find a suitable location to land then maybe one should revise the decision to fly or re route.
2) If you fly VFR ones concern is always what happens if it fails now - where do I go. The same applies on top of any cloud layer. You don't want to be in the position 1000ft above cloud looking for holes.
3) Currency on partial panel IF flying is always a good thing to have.
CP