Object/Models with dynamic sizes and joint movements

I would like to know if it is possible with Unity3D to have an object with the following properties, consider a human for example:

• Leg length can be set when you create the object in your game.

• Arm length can be set aswell.

• It can be set for every part of your model.

• Ability to use all joints of bones of your model programatically.

Also is it possible to run Unity3D from Java? Or what would be the best way to get around with Unity3D having a Java background.

Regards.