[gattilorenz]

“Graag gedaan” (“you’re welcome”, “my pleasure”, but more lit. “I did it with pleasure”) can be dropped quite casually, right?

[jacquesm]

Yes, but it actually does have meaning, and it is appreciated for that meaning rather than ignored.

Conversely:Americans probably think I'm rude because I don't first ask them how they are but start the actual conversation without pre-amble.

[lotsofpulp]

I would find it normal if you started a conversation after a simple “hi” or “hello”, and I think many other Americans would agree.

[gattilorenz]

“How are you doing?” also has a meaning, and sometimes is used in “the deeper sense”, i.e. the literal one.

Graag gedaan is also something you say to be polite, not only when it really was your pleasure to do it, so it could qualify as a phatic expression - I don’t think anyone on the other side thinks “oh well, that person surely cares about me: it’s a pleasure doing something for me!”.