[The Saucepan Man]

I can think of two more examples. Faramir prior to the siege of Minas Tirith, and Bilbo at the Battle of Five Armies (which I always associate with Pippin's near-death at the Black Gate, due to the arrival of the Eagles).

I think that there is evidence to support symbolic intent on Tolkien's part, at least as far as Gandalf's death is concerned. But I would not underestimate the effect of these incidents as plot devices, nor Tolkien's intent to use them as such. He was an accomplished story-teller. He was skilled at engaging and involving the reader, which is just what these incidents do. And I would not view his use of them as heavy-handed, despite their frequency. My own experience, and that of others who have posted already, suggests that they do not stand out to the reader as such. I too was taken in (and distraught) when I thought Pippin (one of my favourite characters) had died at the Black Gate. They are credible because the story involves life-threatening events. Some of those involved are bound to die. And some are bound to get injured (and subsequently recover).

Tolkien was not averse to tricking his readers into thinking one thing and then presenting them with another in other ways either. I have in mind, in particular, the suggestion that the cloaked figure that the Three Hunters encounter in fangorn might be Saruman, but I am sure that there are others. Again, Tolkien the master story-teller is engaging and involving his readers through plausible and skillfully delivered plot twists. The beauty is that we never feel cheated by the actual outcome. Only delighted.

Edit: Cross-posted with Boro, who also pointed out Faramir.