Questions to ask during land buying process

I am looking to purchase a permacuture property in California or Big Island and am trying to lay down the questions I should ask realtors before I decide to visit. After I look at the MLS listing, I typically check on the water situation, electricity, access to the property, whether the lot is hilly/sloped/rolling and zoning. What else should I be ascertaining/asking that can help me zero in on an appropriate property?

Biggies for me are:
What's the sun situation?
Prevailing wind(s)? It's worth knowing about seasonal gales.
I know you've mentioned water, but I'd add rainfall specifically. Any oddities like rain shadows to be aware of?
Has the land ever been used for things like orchards or other industrial horticulture where systemic sprays have been used? Tobacco and apples are generally heavily sprayed here; if we grew cotton in NZ, it'd be at the top of the list...

In California make sure you check on your water rights. Who knew that you may not be able to utilize water on your property without a special permit. Ask if a ground percolation test has been performed. Along with certain crops being grown on the property look at neighboring properties to see if they have had commercial use and what the use was. Aside from horticulture pesticides you also have commercial waste from neighboring properties. Check local laws and rules for the zoning... we discovered that a zoning for agriculture could prevent us from building certain buildings we wanted. (Specifically a barn with a small apartment) since that would be considered multiple dwellings and on the property we were looking at could only have 1 dwelling.

A few things we wished we'd done on our last property search:
1. What's the phone and internet situation? As you get into very rural or mountainous areas, both can get iffy, and it's no end of frustration if you are coming from a situation where speed and connectivity are a given.
2. Try to get a clear picture of the microclimate. The Designer's Manual shows the ideal building site as halfway down a slope, particularly a sun-sector facing slope. We discovered that even though there is plenty of valley below us, there are higher hills on either side.....arguably we are near the valley floor, which means cold air settles or flows through the site. So, even though we are Zone 9 on any map, we had two nights of 12 degrees F. the first winter.
3. Have people been farming, gardening, lawn-keeping, etc. before you? If so look very carefully for invasive plants and insects. We made the unlucky discovery of bermudagrass in the yard in several places; which is an introduced plant here and would have likely been possible to locate away from.

Thanks for all the wonderful responses. Really appreciate it.

Alder, I am Nor Cal as well, in the SF bay area. How about you?

Barbara,
I am amazed that you need a permit to use the water that is right on your property. Its a bit shocking. Is there a good source on the internet that you might know of which gives info on California water rights?

California Water Resource Board You will also want to look at your local county laws.