MapPLUTO's footprints aren't for the buildings, but rather the boundaries of the property. It's a big shapefile for each borough. Totally worth exploring. It's got an insanely detailed metadata breakdown that explains a ton of the eccentricities.

As for the dates, most are guesses. If you plot the dates, you see they're overwhelmingly years that end in 0.

Right. That's what I was using when I was playing with the pluto data in openGl. Unfortunately/Fortunately some of you other programmers are much better than me at displaying this stuff in web apps.