It is quite common to find fine cracks in stucco siding. However, this is not something that should be ignored. Cracks should be properly repaired to prevent moisture intrusion and further deterioration. Regular maintenance can prevent small issues from becoming big problems.
A bathroom fan is quite effective for removing a lot of warm, humid air. However, occasionally these fans are found to be vented into the attic. This can cause serious moisture and mold problems and should be corrected immediately. These fans should always be vented to the exterior of the house to prevent potential moisture and mold problems from developing.