To be honest this seems more like buyers remorse to me.
If you have concerns you have a legal right to return the purchase no questions asked within two weeks, I'm really not seeing anything abnormal and a protractor rubbed over the back of the card is not a good proof of issue. The weight of the heatsink is probably causing a little bending, you've confirmed that the card works fine and the PCB is tiny by comparison to the HSF. It's why people recommended you use a support bracket, I've seen exactly the same thing with numerous cards over the past few generations.
If the PCI-E connector was bent, which is where you're randomly slapping the triangular protractor onto, it would not fit into the X16 slot.