credit scores and credit cards

Hi just a quick couple questions,

About credit scores and records, I wonder what happens after you leave your home country (Canada in my case but it applies to the US as well) and become an expat... how do you qualify for a credit again? Since you're living abroad and being paid abroad, what sort of track would credit agencies have of you?

Also, to cut off residential ties with your home country you may have to shut down your credit cards. If you do so, how difficult it is how does it work when applying for credit cards in the Kingdom?

Thanks again!