Hallo Klaus,
Many questions, indeed. But there are no bad questions, and I apologize that some of those could have been prevented by better documentation from our side ;-)
X-USB with MacOSX 10.6.8 >
CoreAudio supports the USB streaming mode used by X-USB for transmission with different channel counts depending on the OSX version. OSX before 10.4 and 10.5 are not supported at all, 10.6 offers up to 16x16 channels, and 10.7/10.8/10.9 offer the full 32x32 channels. Hence, setting the X32 card to be using one of the 32 channel modes may cause the old system 10.6 kernel panic error.
Unfortunately, the X-USB also requires a firmware update (V8) we just received last week specifically for the old 10.6 system. Installing the X-USB update allows streaming 16x16 channels on old Core-Duo Macs without any problem, but it has no benefits for use with newer Mac OSX versions. There are no issues with X-USB on Windows PC afaik, and there is no need for updating X-USB unless you occasionally want to work with OSX 10.6.8.
Our webteam will soon publish it in on behringer.com. For the time being, I put a preliminary download link for X-USB update here below. It includes the release notes, the binary .BIN file that can directly be loaded to X-USB using the Windows ASIO driver control panel. And it also includes an updater tool (32-bit and 64-bit versions) for updating X-USB from Mac computers.
X-USB firmware downloads:
www.behringerdownload.de/X-USB/X-USB_Card_Firmware_Update_V8_Infosheet.pdf
www.behringerdownload.de/X-USB/X-USB-Firmware-v8_WIN.zip
www.behringerdownload.de/X-USB/X-USB-Updater-v8_OSX.zip
Expansion cards and sync to external word clock >
All the three new expansion cards for X32 allow providing clock sync to or receiving it from external devices. The ADAT card offers sync to either one of the four Toslink inputs or the dedicated WC BNC coaxial connection. Dante manages a specific clocking domain to which the console can be slave (typ.) or master. The MADI card also offers sync to and from external light-pipe or coaxial connections.
Due to the poorly controlled jitter on USB and FW connections, the X32 does not support being clock slave to those connections, currently.
BCF2000 and X32 Edit 1.2 >
You are right, the BCF2000 MCU emulation does not flip any selection/fader layers in X32-Edit. The idea is rather that bank/channel changes affect the channels that are controlled, not the views in X32-Edit. So, as you suggested, you can use the BCF2000 for controlling channels, while viewing something else in X32-Edit.
We plan rolling the next update in time with V2.0
Hope that helps.
Best,
Jan