Danny,
You may not have noticed the distinctions between energy used per day, and power consumption. The energy you require is a sum, concerning a period of time. The power is what is demanded at a particular instant.
If you turn on your stove and clothes dryer at the same time, you could be demanding 5000 Watts of power. Run them for an hour, and your Energy Consumption is 5000 Watt-hours, usually written more simply as "5 kWhr". Run them for 1 minute, and you've only consumed about 100 Watt-hours. Likewise, when you draw an Amp out of a battery for one hour, you have drained it by one "Amp-hour". Drawing 60 Amps from the battery, but only for a minute, is also one Amp-hour.
This misunderstanding has messed up your calculations a little, so it's a little hard to interpret the rest of your question.
The degree of discharge of a battery bank does affect its life, and if you can avoid a 50% discharge after 2 days then your systen is designed for a decent amount of independence. Be careful now with the rest of the calculations. The set of batteries you suggest will (connected for 24V) offer you 1160 Amp-hours. To allow the 50% SOC after 2 days leaves you with less than 300 Amp-hours per day. 300*Amp*hour*24*V=7200 Watt*hours per day.
Before committing to a costly set of batteries, the calculation you need to do next (I can't do this for you) is to evaluate the energy use of all the stuff in your home. Also look at your electricity bills for a year and figure out how much you use in winter, spring, summer and fall. If it turns out that you use 10 kWhrs per day, even in the summer, then your batteries will not supply your desired independence time, even in the summer, even on the sunniest days.
On a parallel track, figuring out how much energy you can expect from a solar panel, wind turbine, or the hydro turbine tells you what it takes to keep and energy supply going to the batteries. If 23KVA really are available from the neighbours, then it's going to be a critical component to your RE system unless you have a falling out.
Devices of different voltages rarely cooperate together, so your belief that you need separate equipment is correct. However, there are inverter/chargers on the market that can charge your batteries for you when the AC of the "grid" or "generator" power is available, and at other times draw from the batteries to supply the AC. I have a Xantrex SW4024 that does this and they were popular enough in their day that some may have made their way from NA to you in NZ. There's modern equipment that does this too, and there are bound to be versions that suit your local AC voltage and frequency requirements.
Using renewables is an education, for sure.
