For the audio crosstalk problem the feeder may want to try a ground loop isolator which are commonly used to eliminate hum or buzz in audio circuits.
I too had crosstalk problems between two handheld BC92XLT's running my KHWD and ZOA feeds.
Used ferrite chokes on the audio and coax cables and nothing worked until I put a ground loop isolator between the scanner audio output and my USB audio devices. The audio crosstalk disappeared!
The particular model purchased was this:
http://www.sonicelectronix.com/item_10297_GS-Audio-GL301.htmlBought the cheapest one and it did the trick!
Hope this helps?
Ken