Arr, before you reinstall--
Go into your FeralHeart folder, and open the ogre.cfg file with Notepad. In there, if the very first line says Render System=OpenGL Rendering Subsystem, then change the OpenGL part to Direct3D9.
This will change how your game renders, and may keep it from crashing so much.
You may also want to try removing any extra maps (.fhm files) from your Exports, to see if that lessens the weight on your computer when it loads FH.
As for your question about particles, it's a glitch in the game that occurs whenever a map is exported. We're unsure as to why, but if you do export maps in the future, go ahead and open your Particles folder and check for any of these 'double files'. It certainly saves some confusion. (This wasn't your problem, though, I don't believe).
But anyway, try the rendering system thing I explained for you. If that doesn't work for you, then save all of your mods/etc. in another folder, and then uninstall/reinstall FH. You can re-add your mods/etc. once it's been reinstalled.