Is there any way to change what the joint looks like? I mean like a joint texture. Thanks.

There are no custom joint textures. You can buy forces or relaxes to colour your joints, though.

I believe there is only one which is custom but idk if you can modify it
-Hector Relax

Nope. It is a collector item only.

easy shmeazy.
http://forum.toribash.com/showthread.php?t=108126