How many years is Kate Anderson gonna serve in prison?
7 years for attempted murder and fabrication of evidence.
Was Kate Anderson really the culprit for attempted murder?
Yes.
The 'kidnapping' she allegedly went through was what she put Riley through. Refer to Chapter 17|Dread, where the doctor mentions her severe injuries. Those are the injuries Riley got from those two burly guys who were working with Kate to torture Riley.
What was the video that Sean showed Xavier all about?
It was the video showing how everything went down in one of the changing rooms and the highway + freeway. Kate spiking Riley's water bottle [remember how she confessed to Josh in Chapter 25|Crazy], the day of the photoshoot after she snapped at Riley in Chapter 15|Snapping at her [The cctv footage in one of the changing rooms she used caught her]. That's the day she instigated to harm Riley. Kate made sure that the cab Riley booked would be driven by her two burly boys. When Riley got in, they offered her the spiked water bottle, which knocked her unconscious [the cctv footage on the highway, freeway caught this]. That day, Riley was heading to the hospital because her doctor had informed her of the recurring tumour. Unfortunately, she ended up getting there all battered and bruised.
How did Riley get to the hospital?
She managed to escape Kate and the two burly guys at the port of shipping containers. Fortunately for her, a car was passing by the remote port area that evening. A kind woman helped her get to the hospital in time for her treatment.
Did Xavier find out who the mastermind was?
Yes, he did. After her full recovery, Riley told him everything, regarding her kidnapping. They decided to play along and act like they hadn't figured Kate out while collecting substantial evidence that would incriminate her. Refer to Chapter 28|A date, where Xavier has a discussion with George. That's when they found everything they needed after much investigation.
Is that why Riley slapped Kate in Chapter 30|Betrayal?
Yes.
What happens to Josh Lambert?
After figuring Kate out, he decided to right the wrong. That's why he testified against her. Maybe he will find someone who can truly love him and likewise?
Does Xavier and Riley get their happy ending?
Maybe?