In Hungarian the people I know use felhő and not cloud. I don’t know what they say in actual IT circles but to my ears “cloud” sounds very awkward if stuck in a Hungarian sentence.
It depends. If we’re talking about e.g. GCP we use “cloud”, but Chmura Krajowa is a Polish product and it has a Polish name, so we use “chmura”.
We basically use the original name in this context.
It seems to me Germans in general like to use English phrases, but on the contrary from other European places I know, they like to use the original pronunciation and spelling. Us, Poles, like to make it sound like Polish, add our own declension and so on.
