The reason you will have to charge a rent that is "all in" (which will cover the electricity, gas and water) is because the two "units" do not have their own meters.  Therefore, it cannot be established who uses what.

You could of course get in touch with the relevant electricity etc providers to understand what the cost would be of getting separate meters installed for this purpose.  Otherwise, you'll have to guess how much electricity etc the tenants will use, and charge them for it in their rent.

I recently took a vague look into splitting water.  A water meter is about $200 (or $300 for a radio controlled meter if the meter has to be installed in a rear yard or courtyard the meter guy won't be able to get to easily).  But then of course there is the cost of the plumber and any materials he needs.  eg he might need extra piping.  If he has to dig under concrete to get to the point where he has to split the line, that'd be costly.  Why don't you get some tradesmen to come and do a quote?  Explain clearly what you intend to do.  The plumber will need a "line tracer".

Property earns capital growth as well as rental yield

These sorts of investments have been referred to in threads on this forum under "serviced apartment".  Search under that and you'll find plenty to read.  The general idea feeling is, they don't seem to have sufficient capital growth. 

Good luck!  Let us know how you go

Richard's userid on this forum is Qlds007.

There have certainly been films made about health problems eventuating from living near those gigantic powerlines.  I've heard people comment that there have been "a lot of people living near them and their power lines that have come down with a case of cancer".  I don't know the costs associated with having above-ground power compared to below-ground.  I don't know if the only reason they're putting them below-ground in new estates is aesthetics, and to reduce the annoyance of the powerlines falling down in storms. 

If you are sufficiently concerned about it, maybe listen to your gut.  You'd be pretty upset with yourself for having the concern, moving in anyway, and later on becoming ill.  You'd always wonder if there was a link.

Of course you can offer 5%.  It's becoming pretty common these days, apparently.  When you are making your offer, you could indicate that you will require access to the property for the purpose of tradesmen measuring quoting etc prior to settlement, and that your offer is subject to that.  And after your offer is accepted, you could go into great detail about just how much access you will require and when, and be sure it is written into the contract.  That way if the current owner doesn't make access possible for you, they are in breach of contract and you can take legal action to recoup costs if necessary.

Getting access for tradesmen to measure up and so forth should not be a problem, and will allow them to start making your kitchen, placing order for carpet or whatever, such that it's all ready for installation after settlement.  It is indeed possible to also negotiate to be permitted to commence the renovation before settlement, but understand that if someone is living in the property, this will incovenience them, and they might want something in return.  eg a bigger deposit.

Remember also a powerful negotiating tool can be a longer settlement period.  Hopefully the property will go up in value a bit while settlement is dragging its heels.  Also your tradies will have longer to prepare everything.

Perhaps put a copy of your offer in the post to the vendors.  If you have the section32 on the property (which the agent should have given you) you will know how to find them.

Either way, if you decide to place an offer on the land, I'd have a "subject to rezoning permission" or something to that effect attached to it.