I'm at a door because I've selected run forward up to that door. Why do I need to click 'open door'.

Because there is a cost associated with it I guess. NVM you are at shrine

It sounds like you're describing a scenario where you're trying to port to a city or other small area on the map that has multiple options when you're zoomed out. If you zoom in some more and target your click on the icon you want, you will only get the wayshrine as the option, which gets rid of the menu.

Though if porting to your house, you'd still get the menu, but that helps out folks who are using their houses for quick porting. Before, you had to always port inside and then exit house, so it was a whole extra loading screen whereas now it's just an extra click.

The confirmation of "are you sure you want to port" helps avoid scenarios where you accidentally click on a random wayshrine off the map, as it can then cost some in-game gold, or if you're in an instanced area, have you lose your progress if the port happens straight away.

Agreed though that when porting from wayshrine to wayshrine, the final confirmation popup feels generally unnecessary.