Response to your first observation is posted under “Salat 1 to 5: One Salat”.
With reference to the tone in Salat, the verse is not stating that you “speak to people in salat.” Rather the verse in question is asking this:
[17:110]: Say, "Call upon Allah or call upon the Most Merciful. Whichever [name] you call - to Him belong the best names." And do not recite [too] loudly in your prayer or [too] quietly but seek between that an [intermediate] way.