Just as an fyi, I shipped my computer from Hawaii to Florida with a Silver Arrow (similar size and weight to the D14) on it and it arrived just fine. That considered, I believe the D14 would have no issues in a pc that is moved around.
As long as you don't horribly botch up the installation of the D14 you will not have any issues of warping or distorting the motherboard. Noctua has tested this cooler through situations most users will never even dream about.
They developed the mounting system accordingly to handle the weight load of the cooler on the PCB behind it. You'll be fine. Just don't drop the PC.