Recurring Payments

I’ve never used Recurring Payments before, hence I could do with some advice from those who know.

As I understand it, a customer needs a PayPal account in order to pay using PayPal Recurring Payments.
* What happens if they don’t have an account? Do they either have to create one, or can they pay by credit / debit card but only as a one off payment?

I’ve read that if you sign up for “Enhanced Recurring Payments” with PayPal, then a customer can pay on a recurring basis and without the need to have a PayPal account.
* If that’s the case, how would they cancel should they wish to? And,
* What currencies do people use this with? I currently bill in €’s, however, it doesn’t appear to be an option for me. Is if available in US $ and UK £ for example?

Thanks in advance.