Just to add some information,
In my map Revolution I have a threeway-connected invisible bridge including an invisible staircase. What I have noticed is that all the bots know their way around it and actually use it aswell if they want to. Especially when playing Thief and/or placing items on the invisible bridge(s). If they aren't too "complicated", bots should be able to use them without any problems.
Also, invisible bridges do not really take up alot of space. You make one intangible tile (most likely #31) and add #27/#28's on top of it (depending on the floor/height) and/or place a threeway tile #11 or just three tile #1's, #2's or any tiles alike.
The way I see this map being made in the mapmaker would be to use the "towers" as good as possible. Meaning, using them to take as much space as possible compared to the sky glitches around the map (if you're going for the out of space theme). When playing on PS2/Xbox, you could use pitch black lighted rooms to simulate the space area (like Lost In Space). All in all, if tweaked enough, I think a possible decent remake could be possible.