Emergency Backup Power Configuration Idea

Here is my plan for an emergency backup power system for my house:
- use an 1800w inverter to power the fridge and water pump.
- get some deep-cycle marine batteries to power the inverter (ie. it is scalable backup power)
- get a 12-volt generator to charge the batteries
- can also use solar to charge the batteries at the same time
- can also connect the car to the batteries in a pinch which frees the generator for something else if required...
- the different 12-volt inputs would require some voltage regulation if connected all at the same time, but that should be doable.

Attached is a crude picture for reference.

Going to return the PowerHub thingy, but there is a problem... the 3000 watt generator I bought for $800(incl tax) does not have a 12-volt output, and has some other limitations that don't work well in my planned application, but I can't return it now that I've used it (for a whole 6 hours).
===} Make me an offer...