Kenwood DNX521DAB issues

I have a couple of problems that I'd like help with please. My 2012 Fabia had this head unit fitted by the dealer and I'm using an iPod Touch connected with both a lightning cable and a stereo mini-jack from the iPod's headphone socket. The sound is fine but I sometimes get a faint buzzing sound. Is there any way to just use the lightning socket without the headphone socket too? (there's no audio unless I connect the headphone output).

As an alternative to the iPod, I can play audio files fine from a micro SD card or a USB stick, but the beginning of each song fades in rather than starting at the normal volume. is this fixable?

Finally, is it free to keep the UK maps updated or is there a charge?

Thanks!