Quote: "Is there a tutorial on how to get a model into X10 with other textures, normal, specular, illumination etc?"
http://forum.thegamecreators.com/?m=forum_view&t=120555&b=33
Quote: "for example if you wanted to create a four limbed creature that moves differently than the base skeleton can this be done?"
http://forum.thegamecreators.com/?m=forum_view&t=96153&b=24
Quote: "how do I add the other textures, 2nd- can I use custom animations and skeleton?"
Just use an existing .fpe for one of the new characters in X10 which uses the additional texture maps and amend it for your model.
*Note: You can only use 1 texture file for characters in X10*
Yes you can make all the custom animations your heart desires. Its recommended to keep all the existing animations and add yours to the end if using the pre animated bi-ped. For a 4 legged creature you would need to animate from scratch.