Don't see why you couldn't.

This is an SOIC16 adapter board I cut for SOIC8 parts:

 

Generally yes. It's a good idea to inspect the cut edges to see if there is any copper foil sticking out that could short to something. Usually there won't be. If so, a file should take care of it, as well as making the cut board cleaner in appearance and less likely to give you fiberglass slivers.

 

Hi KT,
Using a steel rule as a blade guide, cut a score line on both front and back of the PCB, using Stanley knife.
Place PCB on the edge of a table, along the scored line, with the copper track facing upwards.

Hold the PCB on the table with one hand and apply a downward pressure on the over hanging half of the PCB and it should snap in half.
E

 

To make the method of "score and break work reasonably well, the material should be scored from both sides, with the scored lines exactly opposite.
Otherwise, saw very slowly with a 32 tooth per inch sharp hacksaw blade.

 

Laying a piece of sandpaper on a flat surface and rubbing the edge of the board along it will give a smooth and very straight edge.