Reality check #1. You are not protected at all, you are entirely at the mercy of a judge at the end of the day in any divorce. Generally speaking you"re probably going to be ok, but PREPARE, until proceedings are finalized, you could literally get fucked over at any moment. You need to have a backup plan for what happens if everything falls out from underneath you.
I"ve mentioned it in the past, and people love to jump down my throat about it because they love to think their situation is somehow special, but...
Reality Check #2. Your wife being insane, a cutter, and a potential hazard to your child has granted you statistically an ~8% chance of actually getting FULL custody.
This isn"t meant to be a downer, and as stated above, I"m sure you have a million reasons as to why YOUR situation is special, but don"t delude yourself, prepare for the emotional impact of the LIKELY scenario.