Re: "Organic" Fertillizer
I use both. Organic fertilizer isn't any safer than chemical fertilizer. Placing organic material into the soil provides slow release fertilizer and also improves the soil while chemical fertilizers will provide a significant amount of nutrients when you feed the plants.
Plants can only take up non-organic forms of nutrients (with the exception of urea - only a small amount - urea also breaks down into ammonium and nitrate).
For example, ammonium nitrate has both plant available forms of nitrogen. If you provide horse manure, the nitrogen will break down into ammonium and nitrate.