I tend to do room maps in vector. I just grab a bunch of shapes (usually rectangles) you can resize them, and when you have what you want, merge them together and stroke them. Not sure if you know, but in photoshop you can use a hard square brush and hold down the shift key to draw straight lines. If you hold down the left mouse button (PC) and the shift key together and move the mouse it will draw a straight horizontal or vertical line depending on the direction you move the mouse in. That might save you a bunch of time! Enabling the grid helps to keep things straight too.
As for alignment, if you draw your pillars as quick shapes, you can select and align them all using the alignment function.
Hope this helps!