I have played the others route with lots of Quinn scenes. The story stays mostly the same with Rio questioning why she always gets dismissed and Quinn confiding in Lily. Rio starting to think about relationships. Rio fighting with Quinn over the smoking for free accusations. And Lily there taking Quinn's back. Quinn discussing with Tommy if she can trust Lily. It all points to Lily becoming Quinn's new right hand no matter what path you take. And don't forget, Quinn is all about that chess strategy. Having your next move planned ahead of time. She can be in cohoots with Vinny, just to screw him over in the future.
The reason Quinn confides to Lily is becouse Lily has dirt on her, that if it comes out would do her more harm.
That is untill Quinn finds dirt on Lily, she'll directly turn on her.
Even as Rio asks if she paid enough this time, seeing tommy told Rio that Quinn said she was smoking for free Quinn was already thinking on lies to turn things around to not look bad in Rio's eyes.
As for Rio's kidnapping, seeing Rio is already digging to far into Quinn she sees her as a disposable pawn, and is propably relieved. while doing nothing to search for her, not even giving into the demands of Vinny. the only problem that might pose for Quinn is if Rio comes back and tells everyone that she did nothing to help Rio, if Vinny is smart he'll propably let Rio hear his phone convo with Quinn, so that Rio knows where she stands.
And if someone else does find out about the kidnapping and does try to find Rio safe and sound and then tries to confront Quinn, she'll simply say, its none of your dmn business. That is if they can get past Vinny with a Gun.
The best solution to that is if we can get help from the Dik's, Hot's and our close friends. but we'll propably know who will be absent during the search, someone who will advice against the search, and someone who will pretend to search.
So to sum it up. well we all propably can guess the outcomes.