Hi Greenbunny,
I live in Southern CA, Zone 9. I have stevia plants in my backyard garden, but I most often use the plant that I grow indoors in a pot in my kitchen window. I found it as easy to grow as any other herb. I grew all my plants from seed purchased at Seed Savers:
http://www.seedsavers.org/prodinfo.asp?number=982 .
As for agave nectar, according to "Sweet Deception" by Dr. Mercola, it is a liquid form of sucrose--chemically no different than refined white sugar. And many sources agree that agave nectar cannot be produced without heating above 118 degrees. Whether heated at high temps or not, agave nectar is obtained only through processing, thus is not a raw food.
As for your sensitivity to honey, it seems like the concentration may be your problem. Dates are concentrated, but the fiber slows down the digestion of the sugars and it enters your bloodstream more slowly. Same with fruit juice--while cellulose fiber is removed by juicing, another fiber, pectin, remains and slows the process, though not to the same degree as cellulose.
Stevia and dates are now my only sweeteners, and I have found that I don't need anything else now that I'm used to that.
Sandi