CRB only means you haven't been convicted the day the check was run. Bit Like an MOT means your car was road worthy that day.
No it means that there has been a check on your criminal record, or absence of it. It is then up to the employer whether they employ someone or not.
I know someone on the sex offender's register and he is not a danger to children - it can happen. You also said he is no longer on the register, so it is a conviction that is a few years ago and he no longer has to notify people of his status. He will also have had treatment.
BTW do you realise how easy it is to become a criminal and be required to register as a sex offender?
If you are as old as me you will remember Samantha Fox making a fortune by posing on page three. Many of those photos were when she was under 18. They are now clasified as child pornography. Even pictures of her posing fully clothed, if she was posing 'suggestively' are classed as child porn.
I'm not trying to belittle your view, IMHO your istinct is more important, and you were there, I wasn't. I'm just trying to illustrate how something that was mass produced 30 years ago is now classed as porn.
So, suppose you move house and rip up the carpets, the people who put the carpet in could not afford underlay so used news papers. You throw the carpet and news papers in a skip in your garden. PC plod comes along and notices the papers, knocks on your door and you are now a sex offender, you have been in possetion of child pornography and by throwing it in the skip you have attempted to distribute it, possibly exposed your own children to it, and other peoples' children.
Are you inocent? No, you are guilty as hell because that is the way the law is written, but you probably don't feel like a peadophile, you probably don't think your chlidren are in any danger and that you have harmed them in any way.
Yes that is an unlikly scenario, but not totally out of this world.