The Utilidor (tunnel) is laid out like a large circle with a central corridor running north/south through it. Where the Cast Members get off the bus would be at the "south" end of that corridor. That is approximately behind/under Cinderella Castle. The Mouseketeria (read: food) is there. The other end of that tunnel is under Main Street USA. Then the circle branches out to the other lands. For example, if you enter the tunnel, and then turn left, you head to Tomorrowland first. If you turn right, you go towards Liberty Square and Frontierland. It takes 10 to 15 minutes to navigate from one end to the other depending where you are and how fast you walk.

There are also "pargos" which use the tunnels. They are like an industrial golf cart used for carrying people and supplies around and under the park. (they are painted yellow)

As for a "Quick Response Team", I would say No. In my 4 years there, I never heard any rumors of any such thing, and it would surprise me if there WAS such a thing. Disney Security is unarmed. They leave Law Enforcement to the professionals. NEVER would a logo of Mickey Mouse holding an AR-15 be sanctioned by the imagineers. They guard the intellectual property right fiercely.

I have been on a walking tour of the Haunted Mansion before opening, and I've seen how they do the effects. VERY COOL! When new Cast Members start in the Magic Kingdom, they are given a walking tour of the park, and the facilitators always tell a story about the Haunted Mansion, and how it came to be. No two of those stories are the same. Each person tells their own version. Disney encourages imagination. They often describe themselves as a company of story tellers.

As for pics, heres a couple:

This is me on the right.

I'm in red.

I have hundreds of pictures from my time there.