first, thanks to everyone who is uploading mirrors! since SP was down, the only space we had available was FP, so that's really cool to have better sources available.
re: kelltest3, what seems to be happening (that i've seen) is that the gug, while walking, somehow starts heading back into the tunnel. i'm not exactly sure why it does that, other than it might be a movetogoal hiccup (the builtin function all monsters use to navigate).
re: gtkr + q1, i wrote a guide to setting it up for q1 editing a while ago;
http://www.planetquake.com/necros/gtkrq1.html
tigger-on wrote one as well, which is more involved than mine, however, both of them only cover pre 1.5 versions of GTKR (ie: versions that didn't have the native q1 support)
as for setting up gtkr 1.5+ for q1, i don't know because i still use 1.4 (never liked the way 1.5 worked). there might be some literature on the qeradiant site on that though. worth checking.
re: FGD
both of us use gtkr and the format for fgd files seem really different to the very simple gtkr format. we'll see what we can do, but it may take a while to figure it out. :P
cheers :)