Small follow up. Well actually not so small but I hope it helps to other worried people.
1. So I have just bought a digital grip dynamometer which confirmed (thank God) that my grip in my left hand is almost same as in my right hand. So I stopped worrying about my minor left hand atrophy. Can be from constant desktop work with PC, I dont know. But the technician tested this area on EMG as well (results on previous page).
2. Neurologist (not ALS specialist though) and some people (thank you) here confirmed that muscle relaxants should not interfere with EMG results. Had a coffee though just before EMG test, reason for high MUPs? Well, who knows. Probably better to ignore it since like I mentioned previously, the results have to be interpreted based complete data set and not just one single parameter including clinical examination.
3. My heavy arm, heavy shoulder, and weakness when holding let say phone, or when showering and holding the shower handle above my head are still present. But I hope it is caused by from bicep tendonitis/shoulder impingement from end of Decemeber. What got me worried is the fact that this was treated in January and symptoms went away however 5 sessions with physio was probably not enough and it came back (we know that nerve injuries can serve as be a trigger to ALS but I guess not in 3 weeks. Also dr google says that it can take from 6 weeks to 3 months to fully heal a muscle/tendon injury, shoulder impingement even more… this might explain the high MUP as past injury but would it be present in neck elbow and hand? Again, who knows). Worth noting is that yesterday a patch containing Diclofenac sodium reduced the soreness from workout with physio.
4. Some twitches here and there (right leg, right finger right hand which is opposite side of the body, lets say twice a day) but during last month only once in my left arm where I had pain/injury in December (see my first post). My understanding is that with ALS patients twitches are constant and does not help when you move (so you just might be sitting or laying in position where the nerve is being pressed). This points away from ALS.
5. For anxious people looking at this thread in the future what I have not mentioned is that in January friend of mine passed away from cancer, young, in his 30s. We were not close anymore but hey, the shrink said this might triggered the anxiety and might have elevated my symptoms to levels that are affecting my daily life (constant self-observing, checking for reassurance online, etc.).
6. There is no doubt that my left arm (dominant) is weaker than my arm. But hopefully the physio sessions and time will make it better. I work with numbers and hey statistics do matter (seen Moneyball?). Chances of a person who is 34 with almost clean EMG, diagnosed by neurologist with no major denervation/reinervation and experienced some mental trauma to be diagnosed with this unfortunate disease and proximal shoulder (since my grip is fine) onset are less than almost none (since my grip is fine I guess), maybe even never happened before.
7. Therefore I decided not to go to that als specialist. Yes, part of me is affraid but the other part of me wants to move on with my life. Time will show I guess, but now I am less worried and more optimistic.