It would, I suppose, be nice to have the whole article before us to answer these questions, but I'll make a stab.

1) I suspect that "enfeebled" is being used nominally here. Kind of like "the young and the restless" or "fortune favors the brave."

2) I think the implied person is the lychnobite.

3) Looks to me like the antecedent of "its" is "the cheerful voice of the magician."

4) "[H]im" is "the enfeebled of the dull-eyed lychnobite of the press."

Just my WAGs, mind.