I just received my GPM Tiger and looking at the drawings the suspension system builds up very similar to the Halinski Tiger and Panther.
Using bamboo dowels is a great idea for the torsion rods, that will make the system strong and aligning the bogies to be level should be relatively easy. I would drill/punch holes (I do envy your Japanese paper drill) in the swing arms (parts 3-3b) so that the dowel will fit into the torsion arm. I bet you were thinking of doing that as soon as you decided to use the dowels. Using dowels or paper rods for the bogie axels (parts 49, 50, 56) and fitting the dowels in to the swing arm will insure that the suspension system will support the model and won’t fall apart.
The real problem is as long as a glued joint is in a shear mode (force applied in the same axis as the joint) the paper, not the glue will just peal away from the joint. Ideally you want paper joints in a compression mode with the force applied perpendicular to the glue joint (god am I nerdy or not). In any event putting a rod through the joint will always keep it from falling apart.
Jim Nunn