I guess I should add some more info... after the pictures were taken, I added a buch of ventilation to the box, front, back and bottom, and 99% of the time the inverter is on I have the lid open to monitor things.
My batteries are wired according to the second method in that link, which he states is the best for two batteries.
My deep cycle batteries are about 6 years old, and likely near end of their life, hence the 11.8v and only taking about an hour to charge with a stand alone battery charger.
The inverter I have has a GFCI circuit already, and when I don't have the cord plugged in, I have a rubber plug cover that I use so it's protected.
This was our first time in 7 years of owning the trailer to camp somewhere without some kind of power, so it won't be used that often as it is, just there for those few times that it's needed.