Would like to know if it will hurt to bottom out 14 inch Sway-a-way air shocks
they are on the back of the jeep I'm building. Or do I need to build bump stops. I do mostly rock crawling not much high speed stuff.

bottoming out anything is bad, something has to give. I would not make the $300 shock give. But I dont think you can really bottom an airshock out as the nitrogen will only compress so much giving you a bit of a last inch or so cushion depending on how much nitrogen you have in them.

We bottom out our Sway A Ways on a very regular basis...it's not an amazing idea and really, you should have some sort of bump in there....even a chepo urethane one.