I live in a concrete block home in SE Florida. The air in the house stinks and I am well aware of indoor pollution. The house is 2 years old and we have lived in it one year. The first year the house was vacant BUT the AC (2.5 T) was kept on. We AC 1800 sq ft with insulated ductwork in the attic. I talked to 2 contractors. They want to stick an outdoor duct into the supply and leave it open. Yea right. I want an electronic damper that I can open say 12 to 4 AM (lower temp and humidity) I want them to exhaust the air from the return located at the other end of the house. They look at me as though I have 3 heads. They want to bring in air all the time and not exhaust any. I say not possible with tight CCB home and few windows. How do I size and buy the necessary stuff so I can hire some one to do the labor. Am 71 and tired of cleaning up other peoples messes!
I use a charcoal filter ahead of the regular filter. My wife has a nose that can smell anything even a football field away. They work great, I buy mine at Home Depot or lowes for around $10.00. Look for the WEB Absorber, ask an attendant in the heating/ ac section. It is a cut to size and comes in 20x25 size. I only had to cut the plastic piece once and reuse with each change. Mine last 6 months.
I live in your area in the same kind of house. Even from 12 to 4 am, the humidity is too much. With your plan, you will rust out the inside of your air conditioner in a year. Not to mention the energy costs you'll sink in to running your AC during those hours, plus the extra hours during the day you'll need to run it to pull all that humidity out.
What you want instead is an energy recovery ventilator. These are an improved version of air to air heat exchangers used up north, except that they keep the humidity out, too.
Exhaust vents in the kitchen and bathroom are plenty for a make up air system. You really don't need a lot of air if used 100% of the time and there is less to go wrong. Having the exhaust in a specific location may help that area but remember the kitchen and bathroom vents will allow air to flow out no matter how tight the house was built. If you are willing to pay for automatic dampers and timers and the maintenance on them you should get what you want. Just remember it may be your mess if you don't consider the advice of a professional installer at some level. I live close to the ocean and it is funny there is almost never fog at noon but almost always at midnight. Fog= damp air.