I don't know if I think the bombing should be every ten days with identical and predictable results, but it is in a very real sense the proof that the aliens are still more dangerous and advanced than the Xenonauts, no matter how well they do with their air game.
Also, relations is perhaps the wrong word to use. If Greenland is bombed a lot from orbit, they are really going to want you to succeed, and they'll really appreciate it when you stick it to the aliens, but their infrastructure and ability to contribute to the project will still have been bombed a lot from orbit.
As far as defending against the bombardment goes, perhaps it should be possible up to a certain degree, but if I were one of the devs, I would add an annoyance meter or something to the aliens, smacking the ape down if he interferred too much with their business. You shouldn't be allowed to protect the Earth perfectly from the aliens no matter how on top of things you are. Firaxis made an artificial dilemma by only giving you a single troop transport and several missions at once, but Xenonauts has to do something else, and the aliens throwing rocks from on high seems reasonably fit for purpose.
