Just to up the SF geek ante, she (Inara) reminded me a little of Dune's Bene Gesserit. Please no-one tell me she starts displaying kung-fu skills and mental abilities
That's a really good comparison!
I think Inara is, basically, a skilled psychologist. There's nothing supernatural there.
I agree with that. It's interesting though that her training allows her to pass through highest levels of diplomacy and power. The possibilities to be more than a sex worker are there and I wouldn't be surprised if some companions are not also spies despite their code most likely forbidding such things.