Thank you for using JustAnswer! I am sorry to hear about the mold you are finding in your apartment. I am a licensed mold remediator in Florida so I can most definitely provide you with some helpful information.
1. The affects that mold has on individuals can vary from person to person because it is an allergen. Some people are more susceptible due to age, immune deficiencies and allergies. The type of mold present can only be determined by sending an air sample or swab sample to a laboratory for analysis. My thoughts are that any mold in the home, at an elevated level, should be addressed by a licensed professional. Keep in mind that there will always be mold spores present. The determination of what type of mold and at what levels will determine whether mold remediation is necessary. If you have any concerns about your health, then I recommend staying elsewhere until the mold problem is resolved.
2. Whether or not you see the spots on the clothing is often determined by the type of material and color. Mold tends to proliferate more on organic materials such as leather. You may notice that leather shoes and belts have a considerable amount of mold growth on them. Because mold spores are airborne, it is highly likely that all of the clothing in the closet is affected. A determination will need to be made as to if they can be laundered or if disposal is necessary.
3 and 4. Both of these questions are related to my answer for number 2. Because mold spores are airborne that is why you are seeing it on surfaces throughout the home. I usually see these types of mold problems whenurance the residence has experienced a period of elevated relative humidity. All surfaces of the residence should be HEPA vacuumed and cleaned with a detergent solution. Consideration should be given to cleaning the HVAC system as well because it has been circulating the air.
5. Getting rid of this mold should be handled by a professional mold remediation company. This expense is sometimes covered by homeowner's insurance. Depending upon the cause of the loss will determine if the insurance company will provide coverage. The only way to get rid of this mold is to HEPA vacuum and clean all the surfaces of the home. This includes walls, floors, ceilings and contents. The clothing and soft good items can be washed depending upon how heavily they are affected.
6. Based upon the description you provided me, I believe that the closet is contaminated as well. It would be best not to unpack the suitcase with clean items. You would just be introducing a clean item into a contaminated environment.
7. If you want to try and get the residence in better condition then start wiping down as much of the surfaces as possible. I do recommend telling your guests about what has occurred because one of them may have a mold allergy.
My recommendation is to speak with a licensed mold assessor and a licensed mold remediation company. The mold assessor can take air samples and determine a protocol on what actions need to be taken to properly remediate the mold. The mold remediation company will then take the protocol and implement the recommendations. Air sampling should also be done a second time after the residence has been cleaned. This is called a clearance test and provides you and the remediator that the remediation was successful and now the air quality is within a normal fungal ecology.
I do wish you the best with resolving the mold problem at your home. Please review the above and feel free to follow-up with any additional questions you may have.