If bulging disc pressing against thecal sac/transversing nerve extrudes downward, does nucleus flow down pressing against nerve or can it seep, around nerve? if seep, can traction pull damage nerve?

All of the above: A MRI of the lumbar spine is the best test to visualize where the extrusion has traveled and how it is interacting with the nearest nerve root.

Listen to body: The degenerative disc that bulges and presses on nerve and causes pain will not entrap the nerve but the pain can cause muscle spasm and forced traction may be harmful. Cold over the nerve and heat and magnesium oil topically over the tight muscles and an anti-inflamamtory diet and anti-inflammatory medication or herbs can be used with gentle traction if one notices a beneficial response.

Disc herniation: When a disc herniates and causes pressure against a nerve, pain, numbness, tingling, and weakness can result. Not only can the disc material cause mechanical compression, but it can also incite an inflammatory reaction that can irritate the neural elements. Traction or tension on a nerve that may be tethered against a herniated disc can also cause sciatic-type pain from a bow-stringing effect.