In Cloudcuckooland, insulting authority figures is seen as a test of skill, flirting with a married woman is a custom to compliment them, and putting your elbows on the table a sign of respect to the chef. It seems Bob has done his homework, and only made to look otherwise.
Only to learn that "excuse me" is not the proper response to a burp in Cloud Cuckooland.
But his behavior is still very rude and ignorant, and still reflects poorly on Tropestan.
But these customs are not done among the nobility, thus being seen as an insult to the Emperor and Empress.
Parodied: Tropestan and Cloud Cuckooland are enemy nations, so Bob's rude behavior makes him a hero back home.
Zig Zagged: Once the Tropestani government hear of Bob's boorishness abroad, they send in Alice, an Ambadassador who can defuse the situation. Bob stays around, but only as a gag.
Averted: Bob does not visit Cloud Cuckooland, or interact with any political leaders from there.
Exploited: The emperor of Cloud Cuckooland had been looking for a reason to declare war on Tropestan before Bob came along, and used Bob's actions as a pretense for war.
Defied: Bob (even despite being very drunk) remembers he's supposed to be impressing the emperor, and so does his best to remain on his best behavior. He also took the time to study up on etiquette in Cloud Cuckooland.
Deconstructed: Obviously, not the best thing for foreign relations, or preventing Cultural Cringe.
Reconstructed: Bob publicly (and without making lame excuses) apologizes for his bad behavior. The emperor of Cloud Cuckooland accepts the apology, and they start over.
Played For Laughs: Bob gets booted out of the country by the emperor. Literally.