She likes charming, wealthy people and so would find Rodolphus perfectly delightful. She roots heavily against his attempts to modulate his wife though; any day Bellatrix does something outrageous Rita can gossip about is a good day for her.
I AM. HERE FOR. FRIENEMY-SHIP. WITH NYX. It's on. It's poppin. Let's do this. Insults and sniping and competition but also they go out for drinks at writers bars together and exchcange books.
I don't think she'd know Kur HOWEVER!! Rita is going to be reaching out to him and his mother soon because she totally wants an interview with them so they can tell her all the deets about how the Ministry tortured them. Spill your grievences out to her Kur! Auntie Rita will put it all over the front page.
Melisande, Elphias, & Hestia are probably generally unknown to her (except by reputation), but the sky's the limit for future interactions.