AIS500 with Icom M506 VHF

[onreceta]

My sailboat has an older Raymarine system, including an E80 Classic, and an AIS500. Until recently, the AIS500 happily shared the VHF antenna with an Icom M502 VHF. But the M502 is ready to be replaced and, for several good reasons, I plan to purchase it's successor, the Icom M506.
The M506 is available with or without a built-in AIS. (Both versions accept NMEA0183 input, and NMEA2000 is also available.) The built-in AIS is attractive, not least because its graphic display will appear on the remote mic which I will install in the cockpit. (The E80 is belowdecks, so this is an advantage for both safety and convenience.)
And so here is my question. Can I, and how do I, connect the M506 with my Raymarine?
1. Can the AIS500 still share the VHF antenna with the M506?
2. Will one AIS interfere with the other?
3. If I were to take the AIS500 out of the configuration (although it performs very well), can the information from the M506's AIS show up and be accessed on the E80 as the AIS500 does -- with alarms, and on the chartplotter and radar screen, etc?
4. How do I connect the M506 to the Raymarine? To the AIS500 or to the E80 or both?
So far, ICOM tech support has only said to ask Raymarine, saying they only deal with their own equipment. (Like everyone uses their VHF in a void?) And the one dealer I have contacted so far was singularly unhelpful. So I'm really hoping someone on this forum, or with Raymarine, can shed some light... thanks in advance.