As I said, you can pull off some switches if you want. THe microwave draws nothing unless it is on. Also, the Xantrex 2.0 has a manual on/off to control the inverter so that it does not always have to be on.bene
I saw in your diag that you plan on an automatic switch for the shorepower/inverter. You sure you want to do that? if the shore power goes out you will automaticly switch even if you don't know or aren't there. and then your batteries could get drained and possibly damages if drained too far. Plus it's another fancy device that could fail more easily than a simple switch.
The thing that will drain you batt is hair dryers, coffee pots, microwave (somewhat... when in use), space heaters, and water heater. The water heater, should you forget to turn it off when not plugged in, is the kiss of death. Hair dryers, coffee pots, etc pull around 80ish-100 ah but they are very short cycled.
Remember, without a inverter - no coffee without brewing. No hair drying. No microwave. WIth us (and kids) that was too much to give up.