What could be causing muscle twitches in calves, arches of foot, toes, thighs, back, fingers, eye lids, etc? I have been experiencing off/on x 1 week

Multifactorial. Your twitches may be related to your underlying hyperthyroidism, but other reasons may include stress, stimulant overuse (for example, caffeine), overexercise, or nutritional deficiencies. Here is some more information: http://www.nlm.nih.gov/medlineplus/ency/article/003296.htm.