I would not be worried about your short run of small wire (if you can consider #1 small). You might also consider running the solar wires to the inverter terminals (if there is space under the lugs) as you will be running large wires between inverter and battery anyway, and save 'doubling up' the wires at the battery terminals.
Looks like a good set up.
The only other problem I can tell you about is that once I ran my microwave a few times on MSW inverter power, it never cooked as quickly, and I no longer use the inverter with the replacement microwave, only shore power or the generator.
Fred.
