If you put a wrench on the strut nut and then clamp the top with vice grips you can check it the nut is tight.

Standard air suspension replacement struts should be able to handle the same bumps as the original suspension. Standard replacement suspension should not reduce the travel.

It is not unusual for new suspension parts to bring other worn suspension parts to the forefront. The clunk could be something else so I would check it over.

__________________
X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas