Unfortunately the TTS decoder is a worm i.e. write once, read many. Thus it is just not user reprogrammable. The only reprogramming that can be done is to the MCU which controls motor and function actions not sound. Once factory programmed onto a blank chip the sound is locked apart from volume.
I do like the departure music idea.
As for the Q1 - I am 74 but one lives on in hope of seeing all these wishlist items on sale. After all it is not that long ago that retro fit TTS was considerred pie in the sky and this time last year who would have thought the Select would be talking to a PC and changing CVs.