I really do think that being able to change sides so easily and with little penalty leads to much hate and aggravation.
How about something like:
For the fist month you can change sides once a week. This lets a player visit all 3 countries and then a week to settle in.
After that your locked into that country.
You have to wait a Month (or a week , 2 weeks, or whatever - just more than 'report all CV locations back to my country, take a long dump, switch back')
and pay $4.89 to change sides.
Or any of many variations on that theme.
Thanks for a great game. <saaaalute>