[MenaceX^]

I didn't read it all, But as I see you're a beginner, For /fuel thing is a gas system.. You can't just /fuel it up.
About the Moving Gate
You do it like

pawn Код:

if(!strcmp(cmd,"/gate",true))
{
  MoveObject(objectname,1000,1000,955,1); // Objectname is the name of the object, 1000 = X, 1000 = Y, 955 = Z 5 degress underground., 1 is the speed of the gate.
  SetTimer(gate,1000*/*seconds*/, true);
  return true;
}

forward gate();
public gate MoveObject(objectname,1000,1000,1000,1); // the Z here is 1000, Which simply gets the object up. To be on it's place.

And here you got a moving gate.
About the /takejob.
You create a menu and each option gives to the player another job type.
About the gate in PD, I'm might sure you're talking on San Fierro PD station.
Here you go a moving gate of PD gate in SF, When you're talking about + Auto close after 5 seconds.

pawn Код:

new pdbarrier;
//Someplace in OnGameModeINit
pdbarrier=CreateObject(968, -1701.414551, 687.750793, 24.665670, 0.0000, 269.7592, 89.3814);
//OnPlayerCommandText
if(!strcmp(cmd,"/pdc,"true))
{
  SetObjectRot(pdbarrier,0.0000, 359.7592, 90.2409);
  SetTimer(barrier,1000*5,true);
  return true;
}

//Someplace
forward barrier();
public barrier MoveObject(barrier,0.0000, 90.2409, -90.2409);

And that's all I guess, I wrote it all here so.. bad identitation, tought.