Go to the cheat menu and enter these codes.

All Build Licenses
LEFT RT LB RT X X Y DOWN UP X

All Build Objects
LT RT UP UP RB LEFT RIGHT X Y LB

All Levels (since landscape is also needed in building)
X Y UP LEFT LB LB RT X Y LT

Ok thats it for me with Amped codes, til I get bored and start randomly pressing again :)
_mega_

Let me get them for ya!
Ok, for ALL AWESOMENESS go to the Cheat menu and enter RB RB DOWN LEFT UP RT X RB X X. Then go to Rider Customization and go to Awesomeness, it will have every single on there. Another is for ALL GEAR, just go to the cheat menu and enter Y DOWN UP LEFT RIGHT LB RIGHT RT RT RB. Ok for now I'll enter one more. ALL SLEDS: RT X LT DOWN RIGHT LB LT RT Y X

Ok, enjoy!
_Mega_