Both good notes, thanks! (had to double check whether it's even possible for apps to detect that button, but it seems like it is indeed - actually this could be really cool with a future auto-playing SRS flashcard feature too, press volume up for "correct" and volume down for "incorrect" as you review flashcards during your morning jog)
Slower TTS should hopefully be included, though probably only as longer pauses between words (we can't really stretch out the syllables themselves any more). What do you mean by "automatic pronunciation"?