Personally, I'd like to see more interceptions.
However, as Mestari recently pointed out, making interceptions easier won't result in more interceptions, because people will just be that much less inclined to risk it.
Therefore, I thought that it would be better to create more opportunities to intercept, rather than to make it easier.
So how does this sound:
"A player is eligible to intercept if they are under the range-ruler (between passer and reciever) OR if they are in the tackle zone of the passer/reciever."
This simple rule would at the same time elimiante the confusion created by the "between" rule, which isn't always totally clear if you are throwing at an angle.
Martin

(I've got more ideas, but thats material for another post).