Forge tools never actually links to SoaSE, so you can just save the tools wherever you want. If you creating a map save it in C:\Program Files (x86)\Stardock Games\Sins of a Solar Empire\Galaxy I've never done anything with the particle effects, but if you do I would suggest saving them as a mod by creating a file in C:\Users\Administrator\AppData\Local\Ironclad Games\Sins of a Solar Empire\Mods then create a sub folder Particle, and save them there. When you load the game go to Options, Mods (it's at the bottom on the left) any folders in the Mod folder will show up, just highlight it and click Load Mod. Doing it this way will prevent screwing up any core files and having to reinstall.