John, the delay settings are for adjusting the differences in distance between various speakers and your seating position. Start with the speakers farthest, usually L & R fronts. If the center speaker is, say, 2' closer, set the center delay for 2 ms. If the rears are 10' closer, set the rear delay for 10 ms.

There is certainly no harm in playing with the settings as Sony suggests. The ear translates timing into distance, so the sound arriving at your ears first will sound closest. I personally set the delays where the actual distance calls for.

As for the last question, yes, use the tweeter as your measuring point, unless you have the tweeters pointing at the side walls, in which case you would use the sound path, from the tweeter to the wall to your ears.

Larry