You are saying:
"Would you honestly go to your tenants unit with their parents there so they can discuss "maintenance issues"? I have an idea of what one issue may be, but I still need it to be in writing."
You don't need it in writing. You just want it in writing.
Since you know what one of the problems is why don't you attend to that problem. Get rid of that problem. You know it is a "problem" so take care of it.
Finish this issue. Go to the apartment with your clip board and let them complain and then you take care of any issue that can be taken care of.
Let them vent. Take care of anything that you are responsible for. Say yes when it is a doable request. Make the visit as short and quick as is possible and say Yes when you can fix something and get this thing resolved. You need your rent, and that is more important then your "rules"
I have tenants that have trouble speaking English. Where would I be with them if I wanted all my requests in writing? I want my rent and I want my property taken care of. That's what you should want.