Not too bad as long as you take precautions. I usually walk around 8km every day and mostly between 10am and noon. Never have a problem with it. Yes I perspire a lot but that is all. In the heat always keep your head and neck covered and take water with you. Dehydration is a major problem. For the record I am in my 70's.
They have already taken over. For some reason the people will not accept what is going on and the government, if you can call it that, are too scared to say anything.
It may not be essential but it is a courtesy which is appreciated by the Thai people and cannot see any reason why you wouldn't want to speak passable Thai if you live in the country. For a tourist not the same.
I use the app as well and it comes up as you say one after the other. Probable because the screen is small so the app adjusts for the best presentation.