As a native speaker I can confirm that using the wrong gender is totally fine. Sometimes even native speakers don't know better. That is what I keep telling peo

As a native speaker I can confirm that using the wrong gender is totally fine. Sometimes even native speakers don't know better. That is what I keep telling people. I think the most important thing to watch out is the formal (Sie) and informal (Du) form of addressing people. Not so much of politeness, but it sounds very awkward if you would address kids with "Sie" for example.