Hello, im currently playing F3 with mouse and keyboard, and desire to keep it that way but i can't interact with repair and such commands on the Pip boy 3000 since they're XB360 assigned buttons. Any way to fix this?

Did you get your game on steam? Without the "Vault Dweller's Survival Guide"? You can get all the information you need here: http://www.falloutwiki.com/Fallout_Wiki
And here: http://fallout.gamesas.com/eng/downloads/videos.html

Yes i bought it from steam, but the problem is, I'm using keyboard and mouse, and sometimes conversations and the Pip Boy have the XB360 controller buttons assigned instead. And there is no sign in the menu to remap these.

Acess the Options Menu from the Main Menu when you load the game. The Options Menu allows you to adjust your gameplay, audio, video, and control settings.

I don't think i made myself clear enough on the description of my problem.

I want to play with Keyboard and Mouse. Most actions work through these two.
However the Pipboy does not respond to keyboard but instead thinks there is a XB360 controller is connceted, wich i have disconnected in hope that it would assign keyboard buttons instead. That is not the case. The Pibboy commands still says the A=green, B=red, Y=yellow, X=blue that should appear if i USED a XB360 controller, but i don't. How do i get Fallout to realize i don't want to use the XB360 controller anymore. It was connected when i installed but not anymore as i turned it off.

I'm not sure, but I think you made the choice of controllers during the game installation. I have check on my game under the settings menu and I cannot find any way to change the controller. If you have completely disconnected the game pad, I think you will have to reinstall the game to change controllers.