What happens if someone steals your credit card? (More realistic, a new account signs up with a stolen credit card...) I know, SIP creds aren't given until the account's ATA is set up (a nice extra address verification), but I do see the stance of keeping things simple and fairly tight, security-wise.

Keep in mind that you could always get an account with a BYOD provider for direct SIP international dialing when you're on the road, or you could purchase a prepaid international calling card, etc., if you can handle the connection fees... IMO, a BYOD prepaid provider in addition to Voipo may suit your needs nicely.