Healings are going on here. Finn is now fully dedicated to a mission he would have missed but for Lydia. In the process he is gaining back the person he was before, retempered and much harder to break.
It will be obvious to the police it took more than one person to do this. Neither of them were tied up, so they were held. The house was professionally searched. Shaun won't or shouldn't be a suspect.
This is generally true. The Vanderbilts, Astors, Morgan, are all gone. There are exceptions shielded by ingenious investments and trusts. But even those become diluted by beneficiaries over time. For instance, the Rothchilds may be worth well over a trillion, but there are tons of them.