Clark As Tuta use zero-knowledge encryption, all your data can be decrypt only using the master key or your password so even they try to steal your data, they can't.
Not sure about potential chat control as I never heard anything like this. See, if you'll use this address for regular conversation then I can't say anything. But, if you want to use it in your personal things (which I've done), I never find anything wrong with it. About 2 yrs old free account still work for me.
Currently, I am finding an alternative of Tuta for regular usages and I can't find anything except Proton