The employee health tasks are a cinch. Keep a good record and you'll be fine.
Scheduling/staffing??? Not many nurses and "No registry"? 'may not be physically stressful but mentally???
Ask them for a week to think about it. See if you can request a copy of the staffing schedule in the last 3 months. Tell them you need to get an idea on how a schedule is made. But you're primary objective is to get a clue how the staffing really is.
Or, take the job. As long as there is no contract involved, you can always get out if you have to. Some people can handle mental stress pretty well.
You have an obligation to abide by the administration's financial objectives, afterall, they'll be paying you your salary. So, guess who the staff will be barking at ?
Have you heard of an MDS Coordinator position? Give it a thought. Good luck!