Nodes in Blender are exported relative the Blender scene's origin (the 0,0,0 center point).  Meshes are exported relative to their parent nodes (usually the object pivot points).  Meshes whose nodes are excluded are automatically re-parented to an exporter generated "catch all" root node at the origin.  Blender's origin becomes the origin of the entire shape after export.

Blender and Torque both use the same right-handed coordinate system.  DTS meshes and nodes will be oriented exactly the same way after export as they are in Blender.  There are some differences in how the data is handled internally by the two (row vectors vs column vectors, for example), but the exporter takes care of the low-level math conversions automagically.

Blender and Torque Front and Back Views

The main difference between Blender and Torque in regards to the coordinate system is the labeling of the axies.  Blender has the -Y axis labeled as "Front" (facing the +Y axis), and the +Y axis (facing the -Y axis) labeled as back.  From this labeling in Blender, you might expect that you would create a player character facing towards the -Y axis so that when you're looking at the character from Blender's "front" view you can see his/her face;  however, this is not the case.  Torque uses the opposite convention for labeling of the Y axis.  When modeling for Torque, players should be facing the +Y axis.  This mismatch of "front" "back" conventions means that you should either model your character facing the "back" view in Blender, or flip the character around 180 degrees after you are finished modeling but before you export.