Hi all, i recently had problems with Fallout 3 on steam, so i bought the GOG version. Many people have told be that GOG has fixed the GFWL DRM issue that the steam version faces, but my game is still crashing on start up. Also, how do i put Vortex with the GOG version of steam?

You are likely running into the common Bethesda Fallout/Oblivion issue where you had a previous installed version (like from Steam). Also, Fallout 3 seems to run into this even without a previous version that was installed.
You need to remove the Fallout.ini config file from your My Documents Fallout save folder (not sure if it is in My Docs directly, or My Docs/My Games or similar).
Once removed, then start the launcher and configure settings like starting it up the first time.

As to Vortex, it found mine just fine doing its own search. You can also just tell it where it is when selecting Fallout 3 in Vortex and checking its settings (sorry, I am not home and can't check directly where this can be done).