Why don't you arrest all the blacks too because they "might" commit crimes or how about all muslims because they "might" commit acts of terrorism?
False equivalence. The colour of one's skin does not define the neurology or the psychology and neither does one's religion, albeit the conditioning practices of adults lying to children to convince them of some unseen 'paranormal' reality creating for them a demon-haunted world, with a judgemental super-being watching all they do during this brief spark of life in order to reward or condemn them for eternity, is a source of normalised toxic dysfunction.
The mistake you are making is by the simple fact of overlooking one incredibly important distinction between violence against other human beings and child sexual abuse, namely, that every one of us is capable of murder given the 'right' circumstances.
Only paedophiles are capable of child sexual abuse.
As for Germany's Project Dunkelfeld, it is just another unreliable attempt to treat seriously mentally ill people in the community. Sure, there may be cases where paedophiles can learn not to indulge in their selfish destructive urges, for a period, but it is far from being anything like a cure and until a treatment can be developed which is reliably able to cure this disorder, then as far as I am concerned, it would be reasonable to keep offenders incarcerated while they are undergoing treatment and until a dependable cure is discovered.
Paedophilia is one of the single most destructive and poisonous toxic harms within our societies, the adult survivors of child abuse suffer a lifetime of mental illness affecting every aspect of their sociofamilial relationships, causing a widening ripple-effect of further and ongoing damage.
It is too dangerous and destructive to attempt to manage it in the community. As I said, whilst paedophiles are not responsible for their dysfunction, an offender has already proven themselves incapable of self-control and should be removed from society permanently until they can be reliably cured. It is the only reasonable response to this poisonous psychology.