Answer to Question 1
Benefits - may have less pesticide residue; no chemical fertilizer
Detriments - reduced crop yields; more expensive produce for consumers; nutrient content very similar in both types; may carry microbiological contaminants from natural fertilizers
Answer to Question 2
First you might surmise that the flavor was not of sour cream, but just a bland cake flavor. The major effect is the poor volume of the cake because of too little acid to react with the soda and produce carbon dioxide Also the cake is somewhat tough/dry from the lack of liquid for hydration and the lack of fat to tenderize.