TIPS:

-Wario:

You can use the flamethrower in the backroom to burn his face and he will slow down.

When he moved, you can hear a sound.

-Waluigi:

He won't enter to your room.

-Peach:

You can use the fire extinguisher or the flamethrower to make her go to next room.

When she gets to the office, you can hear footsteps.

-Bowser:

When he is with Wario or Waluigi, Wario and Waluigi won't kill you until Bowser leaves.