I also hired Dwyer company to get rid of the moisture, seal-paint the walls that are in direct contact with the ground and install a sump pump.Here is the question.Do I need to disclose to the new renter (Section 8) that in the past, mold was present in the basement?

Any wall covering that is attached to the wall where water came in, IS going to be wet behind it (including insulation, if any), and the only proper method of drying it is by removing some/all of the affected area, or using a dehumidifier with tubes inserted between the foundation and the wall covering and high volume fans to quickly (it often actually takes several days to get all of the moisture out) and completely dry all of the materials.

i'm going to assume the blocks were filled with insulation which would take care of the moisture coming thru. 

Has it settled and allowing moisture in the 2' closest?" 

If the carpet needs to be replaced in the living room or other common areas, I'd recommend a very durable, moisture resistant flooring. 

There is significant damage to the upper and lower unit on one side and wanted to see if there were any suggestions for water monitoring/sensor systems that can be placed around the house and even in walls to monitor and alert you of moisture in those areas.

Also as Bill suggested make sure you have a proper vent fan with exhaust, venting to soffit though is last resort in our area ( north east ) due to sending warm moist air out which gets blown back up into the soffit and creates mold and moisture issues on the underside of roof deck.

You may very well need a sump pump, depending on how much moisture.

We are replacing the gypsum board and using a fairly expensive system to replace the moisture barrier and insulation.  

this keeps moisture and wind from coming into the house. you will have a tough time removing and putting anything back. i would recommend trying to treat it.