Why didn't my puff pastry "puff"?
Puff pastry is a laminated dough, with very strong gluten development, so an extra couple of days in the refrigerator should not have caused problems.

450 F seems like a typical temperature, and the time seems in the normal range.

The only thing you have mentioned is that is definitely outside the standard treatment is trimming the edges with a butter knife.  Normally, you want to trim or cut puff pastry with a very sharp knife or pizza cutter, in order to cleanly cut through the layers.  A blunt knife like a butter knife can mash the layers together, making it hard for them to separate at the edges of the pastry.

Still, this should have lead to lopsided or strangely risen pastry, rather than a complete failure to rise, especially in the center.

The other possibility is that the dough was too warm when you rolled and worked it, or that you rolled it too much, which would work the fat or butter layers into the dough phase, rather than keeping discrete layers of flour then fat, which is what allows the rise.