Regarding #3, I realized that my difficulties to speak are related to the fact I never bother formulating thoughts clearly in my mind, I just accept the concept as soon as it pops into my head and I understand it. But forcing myself to speak as I would IRL when thinking (and reading too) is helpful in order to get more comfortable with the flow of words, instead of having to improvise the formulation as I speak, without practicing in my head ever.