I looked at the batteries and thought about the need for overcurrent protection there.  Then I read about your plans to add breakers.  I have a breaker now on my line to the inverter, and some of those small in-line blade fuse holders for the dump load, solar panels, and other stuff that is attached right at the battery.  I've seen a couple of lines on peoples systems where they accidentally shorted the wires away from the battery and melted the insulation.  It seems a possible way to start a fire without overcurrent protection for the cables.  I have been planning to run one large cable with a large fuse right at the positive terminal of the battery to a box with a smaller breaker to protect the line from the battery, which would then attach to bus bars which would beed power to breakers through which everything else would be attached.    

I have also been thinking about grounding, and have attached my inverters ground to the same point as my homes electrical system, which is my incoming metal water pipe.  I can disconnect my solar panels from my combiner box on the roof, and I have an extra ground line from there, but I still have to ground the frames and racks there, which I plan to also tie to the water line ground.  I also plan to bond the negative terminal on the DC side of the panel box I described above to the ground only within that box, although I want to check if it is bonded within the Trace inverter first - although I don't think it should be as an inverter should be a servicable item which could be removed from a system.  

I like the indicator light and voltage meter remotes to your office.  I have to walk to the laundry room to check the voltages ect., might have to rig something similar to yours.  That way I don't have to walk to the laundry room to see if its sunny outside.  :-)

For your small system it seems to make sense to avoid the extraneous losses from an inverter if possible, but once you add more panels, you may have to search harder for 12V. loads to power.