Yea i find it quite hot too. The same occurs when using the fm transmitter for me too, so i didn't think much of it.

Regarding the question on changing the spoken language. To change things like "onto" and "street" etc, you will need to modify the html. I cannot remember the exact place and I cannot even look it up as my laptop's gpu is fried and so it won't turn on

The other change you'll need is the espeak language under the espeak tab. That will ensure the correct accent is used when words are said.

You can also record your own version of "onto" in your language and it will be played instead of said. You'll need it as a wav without the .wav extension. I sadly cannot remember where you can put it so it can be played, but i think it was the languages folder.