Too much baking soda or baking powder usually results in a too salty and maybe bitter to some kind of taste.
When using GF flours, extra BS is usually in the recipes to help make it fluffy. I've seen alternatives that include a mixture of powdered egg replacer, cream of tarter, BS and Baking Powder with Xanthan gum.
A note on Baking Powder, but sure to get the non-aluminum kind, the aluminum kind does give a horrible flavor not to mention all the bad stuff about aluminum.