I committed a fix for the missing XAUTHORITY problem, it should appear in version 0.95.
Supporting X servers started with startx is something that I can't/won't fix. For such X servers it's impossible to find out what user is running them, and the effect is that you don't have any way to get the authority to change the display. Also, it's not a very common situation. The "what to do on closed lid" thing will be fixed, but not now. The radeontool call has been moved out of the loop. A further thing that still needs fixing is handling text consoles. Currently, only the currently active X console is blanked, but blanking the text console is probably required as well. If you have any comments, or if it still occasionally doesn't work in 0.95 (while X is active), please let me know! Cheers, Bart