Ebay doesn't make postal service mandates. They may limit what you can do on eBay but that is all....unless it is a postal service mandate. You can always call 1-800-ASK USPS.
I ship to Russia all the time but use a third party insurance if necessary( I prefer u-pic...hate hate hate shipsurance)...and mostly First Class international registered which is good up to 4lbs. I haven't had a problem so far.