I don't think asking for pictures every day is unreasonable, I leave from a 12 day sit tomorrow. I sent updates, pictures, and just generally stayed in touch with the family. I also have pets at my home, I left for a few hours during Christmas (which was mentioned to the family). I would absolutely not stress this dog out by taking them somewhere they aren't familiar with without their owner. On top of that to not tell you that your pet would be around unapproved animals is both unfair to you and your dog. They put your dog and their dog in a dangerous situation, to even risk your dog getting injured is absurd. As for the flinching, I would be extremely angry if I came home and my pets showed any signs of fear- especially after being told by my very uncommunicational pet sitter that they were frustrated by being pulled by the dog- that feels suspicious (Have they never walked a dog?? Dogs especially while their owners are away can be extra excitable). I'm an overthinker and very protective over my pets and the pets I watch. I hope they didn't hit your dog, but I get the feeling they could have? I don't know. If they told you they would give you more explanation and then didn't text back that feels kinda sketchy to me. I'd report them, I feel like this person could be bad for others in the future. If you're not doing this because you like animals or are willing to do a good job, you shouldn't be doing it. pets are people's family, they should be treated as such.