delete faces but keep edges

 say you got a 10x10 grid and you just want the borders...

use a divide sop with "remove shared faces" right?

Yes, but... the shape will remain filled. So how do you get rid of that face, but keep the edges?

Use the "Ends" SOP. and set the closeU parameter to "Unroll with shared points"

Woop.

Cutting/slicing up an object in equal divisions

 Houdini Quick tip - slice equally - YouTube

Sometimes the Boolean Fracture lets you down, so use the Voronoi Fracture, and feed a line into the second input. That is pretty much the gist of the video.