Japanese Interjections (Danseigo-Joseigo)

I wrote a (term) paper on this!

Anyway, based on the secondary literature I read, danseigo/joseigo is way more prevalent in media than in 'real life', but it does also exist in real life.

Quoting myself (which I hope is okay):

[...] More substantially, Okamoto (1995) carried out an analysis of the conversations of ten female Japanese-native college students, in which she analyzed recordings of conversations and the use of forms, which she classified as masculine, feminine, or neutral. The vast majority of forms used were neutral, and all but two used more masculine-classified than feminine-classified forms. Further research done by Okamoto suggests this might be a generational change.

(See Okamoto 1995, p. 303f. available here for more details)

Joseigo is also still important for sounding stereotypically feminine, where that's still desirable, e.g. to attract partners. There's a bunch of self-help books teaching that women's language makes you more attractive. (Nakamura 2014) I personally have also seen quite a few of these googirl cartoons seemingly making fun of women speaking in male language - but I might have been misinterpreting these.

Wikipedia has a list and AFAIK there are still many words used by primarily by men or women separately even though there’s some cross pollination so to speak.

One example that comes to mind is the sentence-ending わ: it is described as feminine in many textbooks but it’s also used by men nowadays (though possibly in a different manner).

Using your first question as a Google query produces the link to this research article that suggests that nowadays women are also using danseigo in the workplace.

Regarding the second question, さあな... but in anime, まあまあ which carries additional/different meanings from まあ is used by male characters.