help

hi i just desided to start a skiing game( 3d). unfortunatly i have quite a few problems when i sit down to do the planning. so these are my major problems the rest i''ll try and figure out. 1) how do i do for having a terrain, gravity, random terrain with snow and rocks? 2) how do i make the ice more slippery? 3) how do i save the exact location and time of the skiier? 4) how do i do to have an animation of the skiier turning, falling, ect? 5) is there a way the skier can fall on a probability and learn from it( ie: gain expierance and the probaility of falling goes down)? 6) how do i make gravity and friction affect my skiier? 7) how do i modify these? thanx alot if you want the questions in french or spanish e-mail me