Thanks, guys, that was fast!
To Misalf: I see the TC ascii "penguin" logo briefly, but the "failed in waitforX" is NOT printed after attempting to startx. It freezes either before or after that message. (Although I've fought with that message before during other routine troubleshooting). I am running Xorg 7.7 on both the TC6 desktop=xfwm4 which works on the Mac OK and the TC7 desktop=flwm which doesn't work. I have a xf86-video-all.tcz stub extension whose .dep file pulls in all of the xf86-video-*.tcz extensions. I haven't delved into /etc/X11/xorg.conf before now, but I can see there is a lot of discussion about it. I am checking OpenBox now.
To Jaunito: Good to know about your WM and corepure64. My core 64 is not the pure configuration but I will take a look at that. I'm using rEFId v0.10.4 (which takes me to the TC7 command line no problem, and previously takes me to TC6 Xorg 7.7 desktop=xfwm4). I will focus on the Xorg drivers more, as you suggested. Thanks for link, lots to digest there.
Again, thanks guys!