I just got some new fun toys that I am figuring out a plan to install in my 2021 Grand Design 17mke. not pictured is a Litime Pro 280ah lithium battery with Bluetooth for monitoring. I am planning to install this setup under the murphy bed behind the drawers. Both the DC to DC charger & inverter have smart technology for temperature monitoring. Will the enclosed area be a problem with these components? 

I am planning to build a board to have all components screwed into on the left hand side of the area and I will place the battery on the right hand side. I need to find the inverter prep loop and will be running that through the back wall there. then cutting the spray foam out of the already existing hole to run battery cables to the main power on the tongue of the camper (pictured but very poorly). I have a 300A fuse for the battery. do I need a separate fuse for the inverter and dc to dc charger on the positive run to the bus bar? If so, how large of a fuse for each? 

I will be 4/0 copper welding wire for the runs between the battery and inverter. What size wiring should I be using for the run from the batteries to the tongue of the camper for the main power connection? and what size wiring for 50A DC to DC charger? 

If anyone has any other suggestions or input I am happy to hear it! Thanks so much in advance! This is all new to me and I want to ensure it is done correctly. 

Lithium battery, DC to DC charger, and 2000W inverter install