I'm going to answer this from the perspective of an engineer who has worked in similar environments and who has had leadership changes that went well, as well as ones that didn't

Basically you're describing an environment in which people aren't doing as much as they are capable of, they were working in a hostile environment in which threats were common, and there's a sort of lack of accountability + poor communication / collaboration.

Okay first thing, I wouldn't recommend using analytics to hold people accountable. Not yet anyway. It's a carrot and a stick problem and bringing out the stick first... you're likely to add demoralized staff to the list of problems you're trying to solve.

What if instead you talked to everyone and explained your vision for the company and then followed up with each employee over the next week or two. Figure out what their vision for their own career is and what they want the next year to look like, the the next three, the next five. If you can align your employee's goals and ambitions to your own, I think you'll have a lot more luck getting people to solve the disfunction that they can. And they'll be a lot more understanding when you start taking measures to hold people accountable.

Again, just my perspective as an engineer. I would bet you that the people you are working with are aware of the same problems as you. And they would probably agree with you that people need to be held accountable. But you need to be careful about how you do that. Accountability right now probably will look like more micromanagement and intimidation. Paint a picture for where you want to go and commit to helping your people reach where they want to go... well, then accountability isn't such a bitter pill and it will likely be seen as necessary, not more of the same toxic leadership that wrecked the culture last time.