1. Don't know.
2. Imho. the Pali Canon can't be 100% accurate. We're talking about ideas that are orally transmitted for 500 years or so. Then written down and copied time after time. Lost, recovered, translated, interpreted, re-interpreted and so on.
Best way is to look for things that are consistent, I'd say. But, I'm not a Buddhist scholar. Maybe put these questions to Bhikkhu Bodhi or Bhikkhu Anālayo. The last one also does a lot of comparisons between Theravada and Chinese traditions. Could be interesting.
3. I think so. On the other hand, there is also a lot of support for women in Theravada. Ajahn Sujato and Ajahn Brahm are examples of monks doing a lot in support of bhikkhunis. Also the list of monasteries for nuns worldwide is growing. F.i.: https://bhikkhuni.org/beispiel-seite (Unfortunately, the rest of the site is in German.) Progress can't be stopped. ;)
But, yes. Some monasteries still seem to be/act quite patriarchal. Guess, some changes take longer.