vendor finance / loan contract

A few answers for you:

We want to clear (we will need landowner signatures on the application to do this) and build a dam and establish a house site and build on the block. We will need the owners signatures on applications to do all of this. How can we go about this if we are not the landowners?  The Contract could be constructed in such a way that the Vendor agrees to sign and lodge all applications however you cover the costs. In the event that you do not settle however the vendor will have the benefit of your work.

Apparently the vendor keeps the titile in there name until all monies have been paid out. If this is the case, who pays the rates if the vendor is still legally the owner? Yes the Vendor certainly does retain Title to the property until such time as you pay the balance of the loan. In most Instalment Contracts i have done or prepared for clients you would pay for the rate and building insurance.

What happens if we want to sell? trying to sell somthing thats not even in our name ?  It is a good point and one most purchasers looking for Vendor FInance do not ask or realise. Whilst you are right that normally you cannot sell something you do not own the mechanics of such are that you will sign the sale contract with a simultanious settlement with the original vendor.
What happens if in 5 years time we want to refinance it with our bank?

Is it possible for us to purchase a vendor financed bush block, transfer title in our name so we can do what we want with the land and have a caveate placed apon the title for the vendors safety?  Yes it is possible but unlikely the Vendor would agree especially if the Vendor has a loan upon the property or wishes to use the property as security for his own borrowings.
Whilst this in it own right is fraut with danger for you you realistically are unlikely to ever now how he structures his financings. Not until there is a problem anyway.