since i'm not much aware of condensed matter field, i'll only address points 4-6

yes the physics doesn't change with the speaker. but in a talk the speaker isn't the only participant. the audience are watching it and they're going to pick up+ https://twitter.com/sammyIton/status/1348637538848628747

the science as well as other cues. such lectures and talks create an image of it being a "(cis)man field".
when big institutes are hosting lectures that would be publicly available, they could put in some extra effort to mindfully think about representation. that's the least

they could do against centuries of systemic silencing of women voices in science.
and about 6th point there's already a good thread https://twitter.com/Samatha_Mathew/status/1349065870786453504?s=19

also reservation isn't a success scheme. it exists to ensure all population are represented.