To get rich you may have focused your own risk, and focused all your effort into one company. However to remain rich you will need to do the exact opposite: spread your money across a high number of investments, and take very few risks.
Therefore I would run away from all of the wet shaggy dogs which are attempting to gnaw on your hot assets. Also, steer clear of anyone who’s recommending you invest directly in residential or commercial property. Reason being, it is simply not diversified enough, and if you eliminate a tenant, you lose your return!
Look, you have earned the right to not need to be concerned about your money. So if I were you, I would maintain a hefty amount of money (for chances, and because a $5 million home sounds kind of expensive to keep!), and spend the rest in a wide mix of shares (overseas and local), via ultra-low price index funds.
Lastly, you say that you have $1.7 million in superannuation, you can use superannuation to buy investment property up to $1.6 million per individual, which means you might be able to contribute more. If possible, you should.