Re: FreeBSD+Xorg+KDE+7174 freezes if the "RenderAccel" is "true"
On, true, 1, etc. are all superfluous. As the X manual clearly states, you need only do this:
To enable something. To disable it, usually:
Does the same thing, but apparently:
Option "Name" "0"
Negates it. I'd try disabling Composite and removing all the options except the ones I noted above; see if it still locks up.