ok i have 10.7.4 in a working condition (boots and network)
what i did to get keyboard and mouse to work is as follows.
after first reboot go in to the bios and set the following 2 settings.
Advanced - Usb Configuration
Intel xHCI: Disabled
EHCI Hand-off: Enabled
and then use Boot flags.
-v -USBFixBus=yes
then the keyboard and mouse should work.
for the multi beast i used easy beast
and then enabled the intel1000 driver, FakeSMC and mac pro 3.1
i'm shure that more tinkering is needed but it works for me.