Is it ironic that you saved your best commentary for what is arguably the worst level in all of Marathon 2? I don't know, but that was pretty funny.
There is at least one good reason to use the river of slime to move to the second part of the level - there's a flamethrower down there. You did manage to find it right at the end, and then promptly died. It's a bit annoying they put the flamethrower there. It's only marginally useful for the second half of the level, and not at all on the next one.
The teleporter is the way to go in the original (M1) version of the level. IIRC, there is ammo on the high ledge you teleport to, instead of the two enforcers lighting you up as soon as you beam in.