Newbee help 400 Watt Solar setup help

Even though you have a 3,000 watt inverter, I assume you will only use modest amounts of power except for the microwave. As noted above use large gauge cable. 2 awg from panel combiner to controller is large enough and the largest that most controllers will accept. The ANL fuse is for between the inverter and batteries. The panels should be individually fused. Inline MC4 fuse holders are available. Any of the converters are fine. The 6 awg from converter to batteries is fine also. Plugging the shore power cord into the inverter is the easy way to go and acceptable if you use the right components. I would stay with the flooded Trojan T-105 batteries. A battery monitor is a must, Bogart Trimetric or Xantrex Link.