Seems like being so close to the ground it would pound the ground going over large bumps/potholes/steep entrances. Does that horizontal piece along the bottom take all the damage pretty well?
Yes, Yes, Yes. and Yes.
Large bumps, such as speedbumps is a no-no. Its not the front only, but the frame between the wheels that scrape too. (ps. mine is lowered over 1".)
My driveway has a steep entrance, to enter I have to go in 45 degree angle, to exit I have to go in reverse.
Regarding the front spoiler... It is covered under with 3mm aluminum plate bonded and bolted to the spoiler (home brewed system). This aluminum plate takes all the punishing, including dead groundhogs and rocks. Think it as a cheese slicer.
Impractical, yes. But what would you not do for good looks?
By the way, it actually works, at Pocono car is very stable at 150-160 speeds.