Originally Posted by MikeMpls

2. what if there's weather condition that doesn't permit travel and Delta has to cancel the third leg?

You'll be rebooked on the next available flights. Usually this is done automatically.

Delta gonna refund the miles for the entire itinerary?

No.

if not, what's the compensation if I refuse their re-arrangement?

None. You might be able to negotiate different flights if there are alternatives. If there are no flights available and you can find another way home, you can probably negotiate the refund.

If a weather waiver is announced , you should be able to rebook within the terms of the weather waiver.

3. is Delta's policy different from the other three legacy airlines?

Not that I'm aware of.