I agree with most of the points you made, specially that there must be safe spaces, but I don't think an university classroom should be one of them. Your home? Yes. A doctor's office? Yes. The student counsellor's office in the university? Yes. And so on.
"Although a safe space sometimes requires limiting certain discussions"
That makes no sense in a university IMHO. Students could be excused of classes due to previous traumatic experiences, not the other way around.
No discussion should be silenced because the topic triggers or bothers someone. Sure, we can be sensitive about it, and take precautionary measures (warn the students in advance of the topic, etc.), but at absolutely no point, IMHO, should a discussion in an university be limited because it bothers, annoys, disrespects or triggers someone.
Yes, that opens room for some awful, violent and disrespectful points of view, but so many pillars of modern society were once those same awful, violent and disrespectful POVs.