They disrupt life and lifestyle. If someone in my family had described your symptoms and the multiple examinations you have gone through, I think that I would tell them to see a muscle expert. If only to get it from the expert that what they have is not something grave. When asked why he robbed banks, a well known bank robber said it was because that is where the money is. Likewise, maybe this will give you a sense of anxiety relieving advise.
Tremors come in flavors.
They can involve one or all the above. Some medications we use for this are the beta blockers, and some recent evidence suggests that neurontin works just as well with less side effects. We do prescribe baclofen for muscle cramps, but usually in association with spasticity. There are other medications with less side effects that actually work better, such as a benzodiazepine. I hope that I answered some of your questions.