All your original grouping is still present in the OBJ. You may want to simplify this by grouping together all the parts that you want to move as one piece into a single group. Either your existing modeler or UVMapper would be good to do this. Then bring the model into Poser and select the grouping tool. Click on the Spawn Props button. Delete the original model and you will be left with the original model in groups. Open the hierarchy window and arrange the parenting. Finally create the figure.

Nice clean model :)