Willie, please allow for the fact I'm more used to English Banking than that over here...so if I'm wrong about anything perhaps you could let me know.
I think, however, that maybe you're worrying about nothing. The biggest threat regarding my credit card is loss or having it duplicated by crooks who skim the card with those gadgets. If I'm careful, I won't lose it. If I do lose it or have it stolen, providing I report it promptly, I will have no liability for any expenditure unless the bank thinks I was at fault in some way. It's an English card and maybe an English bank looks more sympathetically on this. If I lose cash, it's gone.
When using my card, providing it doesn't go out of my sight, it cannot be skimmed. Modern till receipts do not show the card number on either copy (store or customer copy - I double checked this earlier when using the card) so the number is not available to anyone. A crooked cashier, while handling my card, is unlikely to be able to remember a 16 digit number, an expiry date, my name and the security number on the back of the card. I doubt they could note those details without me noticing it.
Nobody can do anything with just the number. A purchase in person requires the card itself. An online purchase needs the number, an expiry date and maybe the security number too. That's increasingly requested. Also, an address is needed which is supposed to match that held by the issuing bank. So it's very unlikely someone will have all that. An address is not given when using the card in person
Of course, if I buy something to be delivered, then someone will know the address...but then with no card details on the till receipt, they still don't have enough to make illegal use of the information.
But, yes, there is a minor risk.
However, if you give someone a cheque - from those I have seen in Canada - you could be giving them your Bank name, Branch, Account number, your name, address and a sample of your signature. In the wrong hands, perhaps that's a big step towards possible theft of your identity. It's been shown the wrong hands can use this to make bigger problems.