Yes, the courts will know (and possibly also police, I'm not sure). However anyone else will get back a criminal record report that's empty. Like if you need to provide a criminal record for visa purposes, or when an employer requests one, or if a bank wants to decide whether or not to give you mortgage. So it's not that your status as a human being in the eyes of the law are reset, it's that for the purposes of opportunities given to you, you are equal to everyone else.
What about child abusers? People convicted of fraud or other types of corruption? etc. Basically people that never should never be allowed to do certain types of work because it wouldn’t be in the public interest?
I'm not sure, actually. The law doesn't seem to specify, although it does say exceptions can be made, so I figure that's what happens. Estonia has also been known to deport its own citizens when they truly are a menace to our society.