A few things that run through my head: Ethan along with family and friends have left the second house, partly because of Charles and also because of Ryker. While I admit that this CAN keep Charles at a distance, I am more concerned about Kimmy and her family. Ethan, when he offered the house to Kimmy and her family, didn't know how much Ryker's influence really is, but my thought is that if Ryker had been reasonably intelligent, he would have used Kimmy and her family as leverage to blackmail Ethan. Accordingly, I still find it somewhat negligent of Ethan to let Kimmy and her family live there anyway. A better decision would probably have been to ask Rachael to help her out a bit.
My guesses as to why Ryker didn't take advantage of these opportunities:
One guess: Kenji and Kimmy are related, we don't know how important family ties are to him, but it's likely that he didn't want to take the risk that Kenji might betray him.
Alternatively, Ryker is simply incompetent in his role as a villain.
What also crosses my mind is that Damien knows where Ethan would be living for a while after he left house number 2. It would have been an easy target for Ryker and his minions to wait until only, for example, Azel is there and then kidnap her, or even easier: ambush Ethan there and make him an offer he can't refuse.
Why that doesn't happen leaves two options:
Ryker is incredibly incompetent as a villain.
Damien didn't tell Ryker where Ethan lives. This would mean, at least for Damien, that he at least has enough decency not to endanger someone else's mother.
I'm just playing again a bit and maybe someone can remind me of dialogues that might disprove my longer theories. And I remember at least this much, that the "Ryker is incompetent" theory was pretty clearly proven (at the charity event).