First you know all too well there were no human casualties in the destruction of the media building as even the building owner has confirmed there was nobody inside and he has done so before a camera, so don't mention clearly unrelated stuff just do add weight to your arguments, it has the opposite effect. And yes we are currently discussing civilian casualties.
As for your other example, you don't know whether there is a proof (and I don't know that either), however there is a difference between a court hearing where both sides present their proofs and arguments etc etc, and an actual war where you get an intel and you act on that intel rather than present a proof to a random guy at his/her computer on the other side of the world and waiting for their approval. If you said Israel doesn't put enough effort to prevent civilian deaths, I'd still disagree but that'd be a reasonable argument worth discussing. Saying they kill civilians on purpose? It's bs and you know it's bs
So you are basically saying Israel does it just for the lols, just to be evil, at the cost of getting a major negative PR with various consequences (including for example being unable to complete the military campaign against Hamas and thus making sure this will happen again in a few years once Hamas rearms), with no tangible benefits for itself? That sounds like a good argument...
If no one was in the building why did they target it?