Jeff,
I don't know how I missed this thread when you started it. I'm happy that your father is adjusting to his new environment and that you're feeling better about it all. I'll try to remember, but if I don't, when my birthday comes around on the Board, remind me that it's your dad's birthday too.
I went through a somewhat through a somewhat similar situation with my mother several years ago. She had physical problems which finally wouldn't allow her to live alone in her home - my father had passed away 30+ years earlier. My sister, my wife, and I found a good assisted living facility for her to move to but, long story short, she was miserable there. She didn't want to socialize and she didn't want to do anything that would help her physical situation. I saw her almost every day but, in the end, I became frustrated by her lack of wanting to do anything for herself. She passed away shortly before she would have had to go to a nursing home, which would have destroyed her in every respect.
This is one of the most difficult things that parents and children have to go through. I'm glad that you, your sister, and especially your father seem to be handling it well.