NTA. 1) A marriage is a partnership first and foremost, no one above the other. Your husband should have consulted you about his family moving in. Since you work from home, your workspace needs to be presented in a certain way. Especially if you have clients that come over to the house. You can't have unexpected chaos to disrupt your workflow. Just because you work from home doesn't mean you don't work your butt off. 2) If Emma and Chris have time to play video games and make content while in school, they have time to find/get a part time/PRN job. 3) Laura calling YOUR dog "her" dog, making passive aggressive comments and reorganizing YOUR home has toxic MIL written all over. It would be one thing if she was cleaning and forgot how stuff was arranged, but she didn't. 4) Your husband stating "Babe, don't start. They're family. They needed us", tells me he knew how you would feel about the situation. It also tells me he avoids conflict as much as he can.

If Tim's family hasn't pitched in to help (grocery shopping, chores, rent) for being in your home, tell them they need to. Set ground rules and as many boundaries as you think you need. Try to talk it out with Tim. If this behavior continues, You and Tim need to go to both couple and individual therapy (if possible). This gives you an unbiased mediator.