I think a lot Europeans tend to look cheap when tipping in
the US When I was there the tip was pretty much
rounding up the check. So having to give someone doing their job 20% to do it doesn't make sense.
I hate tip jars at fast food places. They aren't doing anything but putting stuff in a bag. Usually I still tip depending on my mood.
Pretty much 20%+ for reasonable service or better at a restaurant. A time limit probably wouldn't change that.
I've left low or no tips a couple times for terrible service.
i.e. nobody came and asked if I needed anything, I had to get up and go get something for myself.
Usually this happens at the type of place where they split jobs. Someone takes your order and someone else brings it. I tend to tip lower at those types of places in general because I don't know who I'm actually tipping.
I try to leave tips in cash when I have it.
One place I frequent told me that the bartender gets tipped on your drinks whether or not the wait staff got tipped. So a zero tip might cost your waitperson some money.