When you want to draw a frame of wooden objects you can automatically divide the position of the wooden objects.  You draw the first wooden object, say, a wooden bar.  Then you take a copy of the wooden bar and put it at its end position (this is important!).

Once the wooden bar is at its end position you can use the divide token (/) followed with the amount of empty spaces between two wooden objects.

Say you want to have 6 empty spaces between the two outer wooden bars (that also means you will have 5 extra wooden bars drawn automatically).  Once you have placed the last object, don't touch anything anymore except the / key and then pass the amount of empty spaces (here: 6).  So, type /6 and then press Enter.

Result: the "missing" wooden bars will be drawn automatically and evenly spaced!

To take a cross section of a drawing you can use the Selection Plane functionality.  Tools -> Selection Plane.

A plane will be shown that can be oriented in the X-, Y- or Z-direction.  Use the shortcut Q for that and play around with the axes (using the arrow keys).

There are arrows on the 4 corners of the the plane showing in which direction the material will "disappear" when you move the plane, to end up with the part of the section you want.

You can move and rotate the selection plane at wish, for example to change the "disappearing" direction.