>chewing with the open mouth?

Internal bodily function. To me that's not far from saying why take a dump with the door closed.

>elbows on the table?

Agree with Mynoriti on this one.

>burping?

Internal bodily function that potentially comes with a smell. Although, amongst friends over beer, we're all pretty relaxed about that one.

>
>past that (mealtime I mean)....
>
>what about:
>
>asking someone to take their shows off when they come in your
>house?

Tracking dirt into the house is very different to wearing a hat. I've never had to mop a floor or scoot around with a vacuum because someone wore their hat.

>
>asking someone to wait to eat while you say grace?

In mixed company of varying faiths we tend to let people do their own thing rather than force something on everyone. When that's not the case, this isn't an issue.

>
>holding the door open for someone?
>

I do try to hold the door open for people, but don't consider it bad if someone doesn't do it. Sometimes I hold a door and a person suddenly decides they're going to rummage around in their purse or pockets instead of walking through the door or check their phones or just stand still in the doorway for no apparent reason while I'm keeping it open. If other people have been through that and don't have time for it, that's their right. Not a big deal.