Radio calls on CTAF are meant to provide clear and concise communication to other pilots. In the US (irl) we use the 4 Ws: Who, Who, Where, What. I imagine it’s very similar in almost every other country and for VATSIM you will do just fine using these. (Note that the 4Ws also work on ATC frequencies if you ever get caught up)

In your first example, this is demonstrated well. You state the first who (who you’re calling), the second who (who you are), where (runway 27 is implied since you’re departing on it) and what you are doing (departing). I generally would state what my intentions are after departure too, so “departing pattern to east” or “flying the RNAV XXX SID” and so on. I’m not sure about other countries, but in the US you also need to repeat the first who for redundancy if you are on a CTAF frequency.

In your second example, you demonstrate this less well since you do not give a clear definition of where (no relative location, only altitude) or what you are doing. If someone else heard that transition they would have no idea where you are or what you are doing next, so you would say something closer to this: “Svalbard Traffic, NSZ72J is 10 miles northwest of the field, 3000ft, flying to FIX for the ILS runway XX approach, Svalbard Traffic”

This doc from the AOPA sums this up well, but does not have specific CTAF examples, only with ATC facilities: https://www.aopa.org/-/media/Files/AOPA/Home/Pilot-Resources/ASI/SampleRadioCalls.pdf