Do Integra AVRs have the distance bug that pre x800 Denon's have? i.e. need to multiply distances by 0.875 to compensate the incorrect assumption for speed of sound. The speaker distance should be pretty close to the physical distance, so it being 1.5 ft over makes me think it could have the distance bug.
The subwoofer measuring 30 ft is not surprising. This would most impact the bass quality in the crossover region. But then again, most AVRs don't do this perfectly anyway; really need a measurement mic to tweak the distance to get the best blending over the crossover.
As an experiment, you can change the speaker distances to some extremes to see if you can hear a distance impact. Like, set both speakers to 1 ft, and then set them both to 20 ft, then set one to 1 ft and the other to 20 ft, to see if you can hear a difference (look for imaging quality/how precise the phantom center image is).