Can I have visitors?
Friends and family may visit you while you are away.  However, it is best if they visit during a holiday so that you can spend more quality time together and to keep you from being distracted.

Can I visit a student missionary while he/she is serving?
Yes!  It is better to visit the student missionary during his/her vacation time to spend more quality time together and to prevent the student missionary from being too distracted from his/her duties.