Does diverting power to two of the available choices have any effect on the game world or ending? If not I will go for the Archimedes2 option as they would be useless if they don't change anything in the game world or the ending.

Please answer using spoiler tags.

This quest somehow is similar to http://fallout.wikia.com/wiki/Solve_the_Gecko_powerplant_problem in Fallout2.

-You could commit genocide to the Ghouls living there either by shutting off the coolant yourself, or conning one of the reactor's tenders to do it for you.

-You could repair the reactor yourself (risking death) or by using the robot to fix it.

-You could repair and then optimize the reactor if you were skillful enough. This would lead to Vault City invading Gecko and enslaving ghouls (if you didn't negotiate a trade agreement between Gecko and Vault City)

These choices lead to different endings, so it made sense solving these problems.

You can read all about the pro's/cons of the choices on the fallout wiki.

http://fallout.wikia.com/wiki/That_Lucky_Old_Sun