Once again, this does not belong in the Scripts Board. You question does not pertain to scripting so it doesn't go in here.
The graphics supplied with FPSC are just simple and mediocre graphics to use for the people starting out in game design.
You seem to making a HUGE assumption here in that all FPS Creators supply you with ALL the graphics you will ever need. You are also assuming that any FPSC created for the non-coding type is capable of handling high poly-count models and beatiful graphics. Do not make these assumptions. You will need to find your OWN gfx if you don't like the ones given to you. Be happy that you were given any in the first place.
The one and only,