As regards getting riled up when people don't thank you for holding open a door or letting them cut ahead in traffic, that might cause me a moment's irritation, but no more.
I hold a door open or invite someone to go ahead of me not because of who they are but because of who I am, or more accurately who I was raised to be (and hope I sometimes am), and the karma I want to spread in the world.
Demanding acknowledgement for a good deed strips the kindness from it, making it worse than if you hadn't performed the gesture at all.
Just IMHO.