I use the students for help often but not when it interferes with their classes. They are usually very willing to help—sometimes too willing. However, you do have the right to have some privacy about personal affairs and in this case ask an adult/trusted friend to help. For some of my travel, I have a student go with me. What I pay for depends on the student’s financial condition but it usually includes transportation and lodging.
I now pay a student who needs the money to dust and clean my floors. In the past I’ve had students cook for me using my money for the food. They cook and we eat together.
I have three students I use on a regular basis to translate lectures and help with some of my research. I pay for the translation if it is for my personal work but for classes the students do it for their own experience. If you need a translator for a lecture or class it is better to try and organise it for the evening or weekend. As I teach a specialist subject and use translators for most of my teaching all of my classes are in the evening or at weekends.