Ok, the source is up now. I have a bad habit of adding "svn" to patch names but not to the pk3 names so one or the other link is broken when I forget.

Word of warning, the patch adds a full 500+ lines of code to g_admin.c.
separating the layouts by teams would be nice so you could mix your different layouts
Easily doable but overlapping bases is too much of a hassle. The mod is supposed to work by randomly loading a layout when the game starts so if it randomly chooses incompatible bases, bad things happen.
(but all structures can be combined in one menu . no necessary though)
The menus are clientside. I can do this in Balance mod though.

save layout output is strange, delta is 0 0 0 for all (not very important)
I'll explain. YOU CANNOT PUT BUILDINGS ON CEILINGS. So please, don't try. Everything falls to the floor. I couldn't figure out how to get the damn buildings to stick to walls/ceilings ... it seems that G_buildItem uses the player's position to apply delta to the buildable so thats what that was about ... but it doesnt tell you anything later on. If anyone knows whats up with that, please patch.
load layout has some cool crashing effect
Unintentional but hillarious.

I still think of /fly command
You can build from spectator mode. Ever had a really good game of humies vs aliens and aliens loose all their eggs, deconned maybe? Turn on layout edit mode and put down an egg using '!build eggpod', it works like normal build and even in spectator mode.
if some1 stands on the spawn place it wont work either
We could killbox the spawn area. I don't know how and didn't want to mess with it for the moment. The mod uses the game's own building spawning code to do the work so it would be messy.
/e2 you seem to lose precision somewhere, most values look as if you casted them to int at some point
source would be nice ;-)
I didn't cast nuthin (see the .875 values...) although the game might. All values are taken direct to and from vec3_t's.