The cash discount is 25% off of rack rates. You can rent points for about $10 each, so you are welcome to run the numbers and find out if you are better off getting the discount or renting additional points. It should be pretty straightforward.
Most times, getting a discounted rate and paying cash is better than using points.
Annual Passholder rates may be available with an even greater discount, but those aren't like to come-up until just a few months before the trip.
With regard to booking, rooms are only offered at the 25% discount if
DVC has reason to believe that the room will be left vacant because no members will choose to book for points. The only way to really know if you will get a room at the 25% discount is to call and ask. I imagine the odds of getting the discount for a weekend night are higher simply because the point costs go up and occupancy may go down.
Would they discount a room at Easter? Possibly..again, because point costs are so high. I don't really know what occupancy is like at the DVC resorts on these holiday weeks.
Another thing to consider would be moving to a lower-class WDW resort for the weekends. Disney will move your luggage for you, and the main inconvenience is that you may be without a room between the time you check-out at one resort and 4-5pm when you can occupy the room at the new resort. If you are planning a Friday to Sunday stay, consider spending the last Friday and Saturday nights at a WDW Value or Moderate resort paying cash. That will give you a bit different "flavor" at the end of your trip, while reducing your costs considerably. And, if you are an AP holder, there would be no rush to book since you aren't locked into a single resort. Keep your eyes open for AP holder discounts for this period next year, and book whatever resort you can get into.
Good luck.