what is the deal with Senran Kagura anyways? I will never be able to understand that. And why is she called Ryona, isn't Ryona that weird fetish about people getting hurt?
Heihachi is a great character and was even introduced to PS All Stars (even though that game isn't particularly that great.) He's a male however, so he may get the same treatment as Gen Fu or Raidou in terms of usage.
As for Harada, he prefers to be approached on this matter rather than the other way as far as I can tell. He's a bit of a troll into following his own methods. Harada would be the type to introduce Kazuya, Asuka, Jin, or Heihachi first, but if TN asks for other characters he'll say no unless TN provides the reason for it.
It's just a really fun game is all, I play it almost everyday as a stress relieve XD. And Ryona is her name because she gets pleasure from pain, humiliation, exhibitionism, teasing, scolding, and being "violated". She also likes being called names
Lili is very unlikely since she's not a default line up to a Tekken roster. At the moment, no one knows what's going to happen next year, but I wouldn't be surprised if there is one last final character (or more for even more surprises.)
I know he and Kazuya had a good relationship when Kazuya was a child, Heihachi locked up Jinpachi underneath Hon Maru since he thought he was being too nice and then he died and got possessed by some demon