Thanks eraserhead. In Bowie's interpretation, Ziggy dies in the final scene (when the infinites tear him apart). So I think earlier references to "death" and "suicide" should be considered a fall from grace or a retirement, rather than a physical death.
After the kids leave Ziggy (Bowie says they no longer want rocknroll), the second phase is where he "sings the news". On the eave of his comeback, he says "you can't aford a ticket" because "I'm back from Suffragete City". But how much is fullfilled is debatable. With electricity gone and Ziggy singing the topics of the day, his new sound is probably closer to folk music than to rocknroll. The final track begins a slow acoustic strumming between C and G.
"RocknRoll Suicide" plays with a number of possible conclusions. Ziggy walks past a cafe, and realises a hopeless situation. Is he aware of his own impending doom ("my death waits there")? Is the Earth already five years older? Or is his popularity merely fading? "The clock waits so patiently on your song" suggests he's retired. And to that effect, it's a "rock n roll suicide".
The line "no matter what or who you've been, no matter when or where you've seen" draws together all his audience and finally, Ziggy steps out from the shadows to offer "you're not alone. gimme your hands cause you're wonderful". His final plee is to "just turn on with me".
Then in the final scene, it is the aliens - not the fans - that seal his fate.
With regard to the arrival in Greenwich Village, it has been suggested that Black Holes not only offer a gateway to another universe, but also a key to time travel. Greenwich is appropriately, the centre of world time.
I am what I play!