Like most things, it depends on the individuals in the boarding vessel, but I've actually had good interactions even in bad situations with the Coast Guard. They actually seem to be familiar with the statutes they enforce and are very courteous. This is in drastic contrast to what used to be the Marine
Patrol (No longer an entity, thank goodness) and local police enforcement. Marine
Patrol was just plain ignorant of the law and a sourly group to put it politely. JSO (Jacksonville Sheriff's Office) conduct a boarding like a car stop with a suspected felon onboard. I have started out all of my contacts with courtesy and wait to see what kind of a response I get. JSO was friendly until they got down below and then started actually blocking my movement inside my own boat - total control freaks. Although I haven't actually been boarded by the Coast Guard, I had a boat sink in its slip while I was away and they were very courteous and professional while the Marine Patrol officer started accusing me of all kinds of fraud and mischief until he learned that I had no insurance
and then started in on the dockmaster.
I've been stopped by various organizations and they all have different cultures with very different approaches to boaters. Sometimes the commanding officer is full of himself and just wants to make some point and you happen to be the next boater. Other times, the group will have the newbie go through the checklist of questions, many of which will not apply at all to your vessel. As long as the others are having fun with it and its in the interest of training, I don't usually mind. When people with power start controlling things without provocation and then start making ridiculous orders or becoming obnoxious, it just creates an unnecessary problem. Be courteous until orders start to cross the line. If you know that an order will put your guests, your vessel or yourself in a dangerous situation, don't be afraid to speak up and if need be, contact their commanding officer if it just doesn't make good sense. You can push back firmly without being nasty about it. Some law enforcement officers have a great deal of maritime experience and some should stick to enforcing laws on land.