Regarding the first question.
Blender will default to metric. The default cube is 2M x 2M. All measurements are metric. If you create an object that is 2m x 1m in Blender, it will be 2m x 1m in ORTS. If you press "N" while in the modeling window, you can see the dimensions and scale of the objects. Objects MUST have Scale, Rotation and Location normalized for proper behavior. OBJECT-->APPLY-ALL TRANSFORMATIONS. For example, SCALE must be all 1's.
As for animations... so, those are more complicated and someone else will need to reply.