Your in-laws are fricking nutbars, but you knew that.
I really feel for you, having to wait until this crazy drunk-in-the-basement visitation scenario finally goes so far off the rails that you've got the legal evidence you need to get your daughter out of it. I know in my legal battles with ex, the most frustrating thing was that pre-emptive measures to prevent something really bad to happen were not on the table - I had to wait until the really bad thing did happen (in my case - ex showed up at Kid's school drunk and put her in his car, staff had to physically stop him from driving off, the police had to remove him and ban him from the premises, all in front of Kid) before I could get protections in place.
For what it's worth - the child development literature that I'm aware of says that all a child needs for resilience is one consistent, loving and reliable attachment relationship to an adult. That's you. By being the best parent you can be, you are doing what you need to do to help your daughter develop the resilience she will need to outlive her father.
You are doing the best you can. You are a good parent.