The problem is, these words have become part of daily lexis for some and they shouldn’t be.
‘Paedo’ just means ‘relating to children’. It’s a Greek word and so we have words derived from this like paediatrician, paedocracy and so on. ‘Phile’ means a fondness for or excessive interest in, hence bibliophile and so on. Thus the word ‘paedophile’ obviously and unpleasantly literally translates as ‘love’ for children. Of course it is anything but love which to be honest is why I don’t really like it but i think it is in common enough usage that people know what it means.
Paedo however, is different. It’s a slang term for paedophile. Slang, as we know, is informal. Child sexual abuse should not be something that is treated as informal, casual, careless, for obvious reasons, it isn’t.
I’ve explained about the history of nonce. It is literally straight from prison and is used because of violence.
Think about those sort of slang words in other contexts. Lezza, trannie, offensive words to describe someone’s country of origin. They really aren’t casually used by anybody.