You may want to change the boat on your profile to the 260 as the Hunter Edge 27' is a different boat altogether.
Hunter never really assigned a max load to the boat but a lot will depend on comfort and the ability that those on board will not interfere with the docking and sailing. If sleeping, then again for your immediate family and you should be the determing factor. So often many will plan on a max load and that should not be considered as some of my customers would ask. I am a retired sailboat dealer and the most knowledgable of the water ballast.
As for Florida law, simply call Florida DNR and ask them what is applicable to a sailboat as to the weight or number of people are allowable but I use to tell my customers to be smart and keep safety as a main factor.
As for bottom paint, you did not tell us if there is bottom paint on the boat already or not but assuming there is, I would strongly suggest you find out as mixing different paint manufacturers may or may not be good. As to the type of paint will depend if the boat will be out of the water for over 60 days at any time. There are bottom paints that will loose effectiveness if out over that length of time and then there are softer paints that will keep its effectiveness if out of the water for a long time.
I would suggest that you find out what is on the bottom now from the previous owner. If that answer cannot be answered, then ask the local yard in the area where the boat will be in salt water or possibly a local marine store for example West Marine which they would suggest. For a softer paint that will keep its effectiveness if the boat is out of the water I used two paints one I think was Micron CSC or a similar one by west Marine which basically depends on the manufacturer. If the boat is to remain in the water all the time, then it could be Trinidad SR by Petit. Either way, you need to find out some answers first and that you will have to ask questions of the local folks and the former owner.
If there is bottom paint already on the bottom, clean off the scum and any other growth and lightly wet sand in order to get new adhesion. Try a spot first to see if the paint does not interact with the paint already on the bottom. If dry sanding, use a respirator and gloves and do this away from other boats on a no wind day as the fine dust will get on those boats and if you do not want angry owners talking to you. In fact rinse off your boat immediately to get the fine dust off your boat again if wet sanding. Some will use a power washer but you have to be very careful with that.
As for the cost new really depended on the gear but expect $35 to $45K. I introduced the water ballast boats and bought all the last of the production line to include the last 2006 model that left the factory.