I've come across rude crew (even ones i've worked with) and rude security personnel. However, the vast majority I come into contact with are nothing but pleasant or polite. By the same token, I've come across a fair few rude passengers but the vast majority are polite and pleasant. The point being, it doesn't matter what you do or who they are, you will always come across rude people.
I don't really buy into the stressful airport thing. Sure, there can be queues but airports are hardly unique in this way are they? If you allow yourself plenty of time, and follow the rules then it's hardly torturous experience. Also, be prepared....have your passport ready, have your boarding pass ready and this will help too. One big stress for passengers IMO is luggage........having to cart it from the car park to the check in etc etc......I can understand that but it's hardly the airports fault is it?