It sounds like Jasper is doing great! I remember when we started Sadie in classes at 5 months old, we would get frustrated when she would forget things, or act like she didn't know what we wanted, when we new she did. Our trainer just kept telling us, she is doing great...she's just a baby!! It was just easy to forget how young she was beucase she learned so fast!

I can't help with the bell thing, we never trained our dogs that way...we just watched what they were doing, and could tell when they started going to the door, or going and coming back. The have gotten better with age and will stand in front of us and cry if just staring doesn't do the trick