I enjoyed the show and I expect to keep watching. The moment Sheri dropped that glass, it was obvious to me that it was not accidentally. I figured her as first to go and probably as an actress hired to fill that role.
I don't think that just because somewhat is declared "scared," he is to be discarded as the possible killer. My current thought is that Don is not the killer; he's way too obvious so far, unless that is also an act. After this episode, I tended to agree with the majority who are thinking Arianna, but it's really too soon to know. I'm trying not to be swayed by people I like and don't like.
Good summer entertainment for me.