Do you have an example/anecdote for the last part? Not sure I know what you mean.

(not op) well, we Germans are very direct. So we would write something like "Can you give me the coordinates? Thanks in advance." whereas a Brit would like it if it was written as "I would very much like to get the coordinates from you. Can you direct them to me? Thank you very much. Much appreciated." (well, my impersonation of a Brit is not the best since I am too German in this respect)

I'm not convinced by that example: I am British and would use exactly the same phrasing as your first example; the "thanks in advance" takes the edge off it perfectly well. The second example is like a bad impression of a subservient butler or something !

A better example is "that's interesting" meaning "wtf is that? Take it away and burn it" I've had to start specifying "not in the British sense" when using the word.

yeah, actually it took me a while to get to that point, with the "thanks in advance" :) I think generally my argument holds true (at least a little bit, but it probably also has a lot to do with not being familiar enough with the foreign language) but as with the example in the OP what's even truer is that emails can VERY easily be misunderstood as being unfriendly no matter the language. Which is why it's very important to use more social ways of communicating, e.g. telephone once in a while (and especially with delicate matters).

"No offence intended" -> "I don't want to face any consequences for what I'm about to say". Although I had a boss who would say it all the time. It was very stressful because I was constantly trying to work out what it was he just said that might be offensive, leading me to overanalyze and wonder if he was the world's best passive aggressor.

Sure, but I wouldn't have described that as precision necessarily, so I wondered if there's a different nuance I'm missing.

there's many info graphic variations rattling around the internet: what the brits say, what they mean and what everyone else understands. As a Brit in Germany it really helped bring to the front that I was not being as clear as I could be in a country that values directness.