I think its still attached. I was looking the bike over throroughly to get a feel for how things were put together/how they work and noticed the battery tube you mentioned. I *think* its attached, but ill double check. Actually, the truth is that i was thinking about having the frame and wheels powder coated and was looking the bike over to get a feel for the hassle level id be looking at to remove everything from the frameKevin, you're pretty much in the clear.
All of the leaky batteries on the 'battery acid' thread are in S4's and '02 and later monsters; those with the 'ST Based' frames. All of the leakers have been GS or Fiamm (GS made) batteries.
Do make sure that your battery vent hose is secured to the battery, some folks with the early style monsters like yours have had the hoses come off, and then had acid damage.