As for other player characters, the only way I want to see any of them is if they're collecting badges and (hopefully) replacing Ash as the new main character. I honestly despise the way this show depicts female player characters. All of them have been portrayed as girly ditzes, and Lyra was the only one who was even shown with badges. The rest (Marina, May, Dawn, Serena) were all Contest Divas playing second-fiddle to a stronger male protagonist (Jimmy for Marina, Ash for the other three), which is not only horribly retrograde but also boring and inaccurate to the games.
Characters like May and Dawn are designed to be protagonists, and when you play as them in the games, they're battling, collecting badges, and becoming champions, not just playing dress up in some beauty pageant. Contests aren't anything more than a minor side activity in the games, and the last thing I want to see is yet more female PCs getting dumbed down into that role. The likes of Green and Hilda deserve better than that.