Yes, I use a spacer and do not plan on taking it out anytime soon.
Remember that you do not want to alter the hook once it is set at all. The back of the hand should remain flat through out the sequence. Some people want the string in the first knuckle of the three fingers, however this is pretty difficult to do since they do not naturally line up. Personally, the string sits just past the first knuckle in my middle finger, and the pad on the ring finger (remember this finger is just along for the ride). The index finger will naturally settle in from there. I also squeeze the spacer between my index and middle finger. This will get the index finger up somewhat and will create a better space between the nock.