you using mac OS x- very close to initial release of the mac pro 6.1 - 10.9.2 - you not upgrade to last one -10.9.5?

you have firewall in mac os turned on?
thats your network connection issue-

your hp display is using the display port connection - and not responding with any screen EDID- and no valid screen refresh values - ( your catalyst crash at startup was when screen reported no EDID ) - it have a dvi port?

the catalyst safenet dongle driver is crashing all the time- not my software - but 3rd party

try installing latest version-
http://sentinelcustomer.safenet-inc....HL&o=all&t=all
Sentinel HASP/LDK Mac OS X Run-time GUI Installation

-

you mixing display port with dvi-
x4 at 3840x2160 30Hz - with 2560x1600 unknownHz
you not try to use all same outputs at 1920x1080@50Hz ?- i thought this was your show requirement?

like i suggested before? so you get 25/50 on all outputs all at same size and refresh?

i do not believe the x4 can do correct EDID and refresh for exact frequencies at this resolution at either 25Hz or 30Hz