I can forsee a number of problems with people using foreign cards, so I'll give you guys a bit of background as to why the C+P system has been introduced, and why a shop should have no problems accepting a signature on your non-C+P card...
Previously, if someone fraudulently used a credit card, as long as the merchant computer had authorised the transaction, and the signatures on the card and the receipt matched (sometimes this wasn't even required), then the cost fell on the bank, i.e. the credit card issuer footed the bill for the fraud.
To cut their fraud bill, the credit card companies started the Chip and Pin system, whereby you'd need to enter a PIN (harder to find a PIN than forge a signature) for transactions. The chargeback system was changed so that if a retailer accepted a signature from a customer who had a C+P card, and the transaction turned out to be fraudulent, then the retailer footed the bill for the fraud, and not the credit card company.
Crucially for you foreigners, any transaction which could not be put through as C+P (either there is no chip on the card, or it is a special card with a chip which tells the retailer to accept a signature - for people with disabilities) would still be treated the old way if fraud occurred. That is, if a non-C+P card is used for fraud, then the credit card issuer foots the bill for the fraud.
Now, from Feb 14th, all the retailers in the country with C+P have decided they don't want to have to pay for fraudulent transactions, so if a customer has a C+P card then they will have to put their PIN in to pay for goods. If the retailers follow this rule, even if the transaction turns out to be fraudulent, the retailer won't have to cover it, the credit card company will.
So, from Feb 14th, retailers will be reluctant to accept a signature for a transaction, because if it's fraudulent, they'll have to pay the cost of it. But this ONLY applies to C+P cards. If the customer does not have a C+P card, then if they turn out to be a fraudster, the credit card company pays the bill - the way it always was.
Perhaps armed with these facts, you'll be able to tell a retailer exactly why they should accept your foreign card, and why they should not be worried about any fraud chargebacks.