Hi David
Yes, you can manage destinations and postage options.
It may take a bit of getting used to but almost everybody on here can help you with it !
I have similar setup, altough I ship to uk only but depending on weight I either use royal mail or citylink.
yes you can do it, well kinda.
my setup is royalmail upto 1kg else city link
and for everyone else outside the UK royal mail small packet service.