I'd make the pass interference rule match the NFL. The current rule encourages interference on any pass over 15 yards, especially if it's a long bomb to the endzone. Why let him catch it and score when you can just interfere with it and give them 15 yards instead? I could see keeping the current 15 yard rule for passes interfered without outside of the endzone, but inside the endzone that should give the passing team a TD.
Another good call. I agree, it definitely creates an incentive to intentionally take out the receiver if the potential gain is over 30 yards. The guaranteed 15 yards is probably better than the potential 30-40/TD if you are beat on your route.