Ok,
So if I want to book a week for someplace in the world passport collection, I see that it is 160 points. Is this per person, or just 160 points and DH and I can both go?
160 points is the "cost" of the villa for one week - there is no per person charge. The allowed occupancy is determined by the resort you choose. There will be no room tax (although a damage deposit may be required at check-in).
The point quantities in the World Passport table are per condo for a full 7-night week, for as many people as the maximum occupancy of the condo (typically 4 for an efficiency, 4 for a 1BR, and 6-8 for a 2BR).
While many studios will sleep 4, many will only let you trade for 2 to get a studio. And remember that MOST resorts are strict to VERY strict about occupancy. They only time NOW you can trade a smaller unit for a larger one is when you have an going search for the smaller one and they offer you the larger one. This happens not uncommonly but no way to ensure it does. Don't ask for a unit size that won't fit your needs.
Make sure you investigate the resort you accept to make sure it meets your needs and expectations and there are no surprises. And don't forget there may be other ways to get the same or similar options besides trading DVC. You may do better through a different route.