Outdated "manners" you'd like to see go away

1. Elbows on dinner table - This one's a no-brainer. Serves no practical purpose. We should be able to put elbows wherever we want.
I've never worried about this one. I want to be comfortable, not sitting stiffly with my hands in my lap.
2. Holding doors open - This one will be controversial. Most of us grew up in the South with gentlemanly stuff. But I think unless his hands are full, there should be no pressure to ever hold a door open for a dude. Dudes can open their own doors. It gets dicier for women. But if we're going to live in a world where women are treated the same as men, we have to apply the same standards. And at the end of a day, it's a door. It's not like we're lifting a car off an infant. People who aren't carrying things can open their own doors
Male, female; young, old; able bodied, visibly injured; hands full, hands free, I look at it as a random act of kindness. Something not expected (I do, however, expect at least a smile or a thank you if I do it).
3. Thanking someone during an arm's length transaction - Like thanking a toll booth operator for taking your money. Or thanking the Popeyes employee for handing you food you paid for. What are we thanking them for? The payment is the thanks. Now if they go above and beyond by getting you an extra packet of sauce or something, whatever. But I think we over-thank in this society
I always thank them. Service industry workers get enough crap from the public. Again, not required, but why not be nice?