Answers (with explanation):
Marriage: Union (A deep merging of two minds).
Time's fool: Subject to the whims of change (Time is constantly bringing change, and to be a fool of someone or something is to let that person or thing control you).
Bending sickle's compass: In its range of impact (A sickle is the symbolic weapon of death, and if you are "within its compass", it means that death is near).
Edge of doom: Infinity (Doomsday is supposed to happen at the end of time, making this a way of saying "forever" or "indefinitely").
