Yeah, it's a pain in the ass. We have 2 apartments hired out, and nothing but trouble here and there.
We consider to sell them and rather enjoy the interests from the capital monthly instead of the rent.
What you can do: Copy of ID, salary certificate for the past 3 months, deposit + the rent for the first month, that's all to collect before handing them over the key. How the situation is gonna look like after few more months, only god knows.