I've looked over the dragon, fun model :)

Here are some pointer:-

• The first order of rotation must be axial to the body part. The only exceptions will be things like feet where the twisting is done in the shin. All the tail sections are currently XYZ. They need to be ZYX. The head also needs to be ZYX. You have tried to correct it by setting the center orientation dials. Anything above 45 degrees and you are looking for trouble.
• I'd suggest adding more annular vertices to the neck. Currently you have each section made up of three rings. This means that each ring has to work exteremly hard. I tend to use a minimum of four rings in these situations.
• Try adding more polygons where the legs meet the hip. You only have one taking the strain between the thigh and the tail.
• You currently have the body scaled 41%. If that is to be your default size it may be best to scale the OBJ file first and create the figure based on that.

What I would do is to start over by writing a new hierarch file and bring the dragon into Poser that way.

However, take heart I know what you are going through, I've been there. Hopefully the above will be helpful. Good luck :)