That's not what i've seen. I've seen white flashes happening, without destroying the ship.
That's likely the remnants of destroyed hulks disappearing. When the broken bits of destroyed ships disappear, they flash white temporarily. It's somewhat different than the ship blowing up flash.
Also, using missiles and reaper torps, I've noticed an incredible spread of hull damage caused by these weapons-that doesn't seem to be explained by armor.
There are a lot of factors affecting the damage that's taken. CR, officer skills, etc. of both the target and the firing ship. For example, the Damage Control skill not only means -25% hull damage taken, but if the target happens to have the elite effect, then the amount above 500 is reduced by 60%.
So I'm saying when armor is blown away from the core, your torpedos might do more than if armor is completely blown away from the edge. If what you're saying is true, then it doesn't matter matter what part of the ship you hit, if it's stripped of armor, it will do equal damage.
No, it doesn't matter where the shot hits, whether in the center or at the edge, it just depends on the armor cells at that location and the cells around it. The ship has invisible cells that exist past the visible boundary so that the math works out that this is the case. They're not shown on the HUD (which only shows the part that's inside the ship sprite) but they do exist.