John C Daley

Would not a plastic lining make everything far worse and very quickly?

Broken tiles can have very sharp edges.
If your drive needs gravel, throw then there and the traffic will break them up nicely
You may have to buy proper clay in.

Do you need a pond?
can you divert the water well away from the house because a pond may allow the water to permeate back to the cellar
By the sound of things something has altered the water flow because I doubt the cellar would have been built that way.
There may be a broken down pipe near the house etc

I have never seen a pig attack chickens

I use passenger or light truck tyres.
Heavy truck tires are very difficult to move.
One thing to note, try and use tyres of the same type.
I actually stack them in a column rather than lay them acros in a brick like format.
In the column set up its easier if each tyre is the same, and I screw the stacks together at each level of tyre.
It create a very strong wall.

Very clever idea

What distance between are we looking at.

I had a bush fire at my place 25 years ago. I rushed in and installed sprinklers over a couple of acres and watered once a month for a few months. I could not cover the whole burnt area. 25 years later it is easy to see where I watered and where I did not.
The difference is alarming. The non watered area is still struggling.

if your want agroforestry, whats wrong with working with what you have, are the existing trees marketable, or can you create a market for them?

Think about planting any trees or shelter belts early, rather than after you build. They grow while your think