I can't corrupt Lina passed open, the guide doesn't show me anything on how to unlock the rest. Also I have talked to Cassidy about seven times about yoga and it won't register that I have, is there a specific way to go about that?
By checking Lina's corruption menu, you should get a list of all the available Nerve she has. If you haven't gotten it, it will tell you the scene it is in:
For Cassidy, you can talk to her most mornings and some evenings. If you want to know all her available scenes, you can check the scene guide and filter by Cassidy:
