Testosterone=brute force! I have two boys, 4 and 2, and they too seem hardwired for battle, per say. Heck, when I was pregnant, it was 9 months of testosterone induced, side-smacking of my poor husband. It drove me nuts feeling so automatically physical. The only advice I have is to tell them what they can do. If they're kicking, tell them in they need to kick, kick a pillow. Or take them outside and let them kick or hit balls. Rough housing is fine, but you must set some ground rules. The where, the when... that we never fight out of anger. As soon as hitting/kicking starts, they are done.
I too have a "Buzz lightyear"! And my 4 yr old is right along with yours in the rude words. We, too are working on that. We don't get angry (that asks for more) we just give alternatives. Hang in there! I'm relieved that my #3 is a girl so there's a break in power battles!