What would the danger aspect of the route be - are they planning to put it right alongside to the A82? I'd hope not, as apart from the chance of getting hit by a stray car, it would rather detract from the walk. Even so, it would still be safer than walking along the road itself...
I've done the WHW twice, and I wouldn't agree that the Devil's Staircase is the best bit - for me that would have been Loch Lomond, or maybe Bridge of Orchy to Kingshouse. The view from the top of the Staircase is certainly good, but the walk up itself I remember as being a bit of a slog, though my view may be coloured by that winding, never-ending descent into Kinlochleven afterwards.
Glencoe is spectacular, even from the bottom of the valley, and it always struck me as a fairly glaring omission from the Way. A there and back route from Altnafeith would certainly be a pleasant way to spend half a day. Alternatively (and possibly heretically) I can see that going from Kingshouse to Kinlochleven via Glencoe and the south shore on Kinlochleven might be more appealing than the Devil's Staircase.