In a real life scenario that I can ad hoc reproduce here on my PC, only point 6 makes sense. With the others I can not agree when looking at my open tabs here.
Sorry to hear that. For me it’s the other way round. While I nearly always use the generic masculine form when speaking directly to others that never happened to me. Then again at work it’s forbidden for me to gender in official postings since I did that once.
What I totally get is that online it’s a totally different experience and no matter whether you gender or don’t you may as well drop yourself into a vet of acid.