Re: english words like "sat" (past tense of to sit) automatically replaced with "Saturday"
Which Text-to-speech voice, exactly, are you using when this happens? Also, do you have any speech replacements defined under @Voice Settings menu - Edit speech?
FYI, the app does not do any of the stuff you described, unless you defined them as speech replacements (Settings - Edit speech menu). Otherwise, your TTS voice does it. Select a different voice, or go to this voice settings and adjust the options there. But please, tell me exactly the brand name of the TTS engine, and this voice name, as I cannot reproduce any of these errors, yet more and more users complain about such problems. If I knew which voice does this, I could advise users how to adjust that voice settings, or to avoid that voice, or file a complaint about a bug to the people/company who make it...