Your dad should seek legal advice.
But if he is lending to a corporate trustee the National Credit Code does not apply as the borrower is not a natural person.

a person not lending as a business wouldn’t be a coded loan either.

you are borrowing money so you must meet all the usual requirements, including ‘cash out’ restrictions.
business as usual.

Good point Richard. Get around it by just not lending to natural persons buying resi property.

A will incorporating a testamentary discretionary trust, or multiple trusts, will cost about $3k to draw up, but the tax savings should be multiples of this, especially if there are non-resident beneficiaries. It might even help with UK inheritance taxes. My understanding of UK inheritance taxes, which is probably wrong, is that it is based on the value of the estate at probate. But probate will be applied for in Australia probably thus bypassing this. If you do have UK assets you could do one wills, making sure one doesn’t cancel the other, so that the UK probate size will be minimised.
You should be seeking advice from a lawyer admitted in the UK – there should be some of these in Australia.

There are other strategies to consider such as triggering a CGT event now, and plan to reduce it. Or you could move into the one with the largest capital gains liability so that when you die the CGT liability on this one will be extinguished and the former main residence’s CGT will be minimal.

It depends. Generally the main residence can be sold tax free up to 2 years after death. But not all main residences are CGT free – over 2 hectares, run a business from there etc.

get some legal advice about minimising taxes. One way may be thru a testamentary discretionary trust.

why would someone sell something for 60% retail price?
When you sell property there is generally a 10% deposit and the rest is paid at settlement. And you cannot get access to the deposit generally.

It sounds like you are wanting people to pay up front, but not get legal title until 2 years later. Don’t think many would be prepared to risk that.

You could set up some sort of managed investment scheme where the client lends you money and you develop with them taking a mortgage over property. But you would need to own it outright.
If you are raising money from the public this will be very costly to set up.

Yes full duty would apply.
Mortgage discharge and registration
loan application fees
conveyancing fees.
CGT needs to be considered

I don’t know about commercial loans with offset accounts but how will you get the cash into the trust?

which country are you purchasing in?