Map Problem... sigh

Hi again o.o
im creating my first map... EVER (on deusex) and imma having a load of problems
first, how do i get a mover to be centered on the grid? id had a lot of problems with this and ive tried toggling vertex snapping and it wont work.. as a result i got movers and doors on an outside wall
... this mover in pic 1 cant be resized cause its a pic of the roof (its a crusher)
2 for some strange one of my entire rooms MOVED... how do i move it back? (the ladders ment to be on the wall)
HELP
im creating my first map... EVER (on deusex) and imma having a load of problems

first, how do i get a mover to be centered on the grid? id had a lot of problems with this and ive tried toggling vertex snapping and it wont work.. as a result i got movers and doors on an outside wall

2 for some strange one of my entire rooms MOVED... how do i move it back? (the ladders ment to be on the wall)
HELP