Hi Ado welcome to the forum and cool kit and plans to start your new hobby (addiction haha)
Can you get some locking pliers on the stripped screw head and try and remove it after spraying down the thread with WD-40 or Locktite Freeze and release ? Give that a go and if no luck Zeromick has offered to supply another bridge or email Adam @ PBG should be able to replace it.
With the dent in the body please post a photo might be able to use a hot iron/wet cloth to remove it. If it's more than 1mm deep then it will take alot of sanding to remove it !