Xilinx ISE Global Signals (VHDL)

No, they don't work. You can add probes in the FPGA editor, or, to avoid having to edit loads of modules to bring signals up to the top level in the code, put 'records' in the port definitions instead of normal signals. These can easily be edited in a package file to add more signals (e.g. for debugging).

Disable McAfee splash screen

To disable McAfee 'Security As A Service' corporate antivirus splash screen, use regedit:

HKEY_LOCAL_MACHINE\SOFTWARE\mcafee\ManagedServices\DesktopUI\Tray\Splash  dwEnabled = 0

 You probably need admin rights on your PC, and I guess this could get stomped by a group policy or something (though it didn't for me).

[edit] yeah this did get stomped at some point, but for me at least this is rare enough to not be an issue (i've had to redo it once so far).