The first time my now husband met my sister's family, my nephew, who was 2, was sitting on the back of the couch with his bare bottom pushed up against the picture window on the front of their house. He has since gotten over the naked phase. :) If you can handle that, then you can just let it be if your husband is also comfortable with it. If there are times that he needs to get dressed, it is better to win the fight of getting dressed when you aren't on a time restriction. You don't need the added stress of choosing to fight that battle for the first time when it could really throw things off.
As for dealing with the fights - my sister would teach her kids what to say to verbalize their desire rather than just letting them throw a fit or turn everything into a fight. For example, when your son doesn't want to get dressed, you can teach him a phrase to say, like, "no pants, please." If you're o.k. with it, you can say o.k., but if there is a reason he needs to be dressed, you can explain to him what that reason is. I don't have strong-willed kids, but this approach has really helped with fighting over toys (asking the other child for the toy rather than screaming and grabbing the toy) and clothes choices. Kids need to know how to verbalize what they are thinking to feel understood.
One other thing I have often heard is that once you choose a battle with a kid, even if you realize it isn't that important, you have to win that battle no matter what. If you let the child win (especially a strong-willed one) they will try even harder the next time to win.
Good luck!