While I agree with John F's comment about posting their policy and notifying customers about cancelled orders, I think you're being a bit unreasonable on your points.

Take the "responsibility" comment. It sounds like you've done this sort of thing before, understand the consequences, and are willing to accept the consequences. The thing is, Kobo doesn't want to pay their staff/contractor to take the time to listen to everyone's story. They most certainly don't want to give their staff/contractor to use their own discretion. At best, Kobo is going to get bad PR from not honouring the warranty that a customer thought they had (because certain people are going to claim that they had a warranty even if the warranty said that it was only valid in the country of purchase). At worse, Kobo will have legal wranglings in a foreign nation because someone is inevitably going to argue that according to consumer protection legislation in their country, such and such must be done.

As for travelling with your devices, people have brought this sort of thing up before. Regulations for the transport of goods do appear to be inconsistent and probably are inconsistent. Yet inconsistencies in the law doesn't allow Kobo to knowingly break the law. If Kobo cancelled an order because they knew it was going to a company that forwards packages, it could be argued that they were aware of the potential for export. (As for the consistency of regulations, there may be a number of factors at play here. Governments may have exemptions for individuals, but not businesses. Branch A of the government may have no desire to implement the policies of branch B of the government. It may be okay to have a device in a country, but not to leave it in the country.)

Anyway, enough of that. I agree that Kobo should be communicating better with their customers. I also think that Kobo's hands may be tied here until they get the approval to export their product to your country.