To my mind you described two different situations. One, in the middle of a large party. Two, Not_party. I don't see him as being rude in the large party situation, but definitely rude if there isn't
I agree with this. Typically when people I know throw get togethers, people just come in - they often don't even knock. And if they do, whoever is closest to the door opens it. (I've been greeted my best friend's door by complete strangers countless times.)
But the idea of someone knocking and just barging in when there is *not* an event/get together going on is pretty appalling.
Part of it is the "I know you're coming."
But I have every sympathy with wanting him to knock, and WAIT, even if you know he's on his way over to loan you a power tool.
So, jus topen up your mouth.
One important thing to note:
Do not tell your dad that what he does is rude (the title of your post).
Tell him what you would prefer he would do.
You don't even actually have to tell him why.
And if he argues, then maybe what you do is, you use the "cut-and-paste" routine, and you simply say, "Please ring the bell and wait for me to answer the door, Dad." "Please ring the bell and wait for me to answer the door, Dad."
Even if he says, "don't you trust me?" or "I'm your father!" You just say, "please rng the bell and wait for me to answer the door, Dad."
The underlying message is, "I won't budge, I won't debate this, I won't change my mind."
And you can too take away your Dad's keys. You just have to take away his "legitimate" right or need to be there during the day. It might mean you have to stop relying on him as a handyman or whatever, but that's probably part of the issue, actually.
If you rely on him to fix stuff/install stuff/supervise the plumber, then you ARE telling him that it's partly his home too.
Maybe you need to change that first, actually.