Right, Ok so my misunderstanding on this scaling debate comes down to one question.
Assuming vast quantities of transactions, and no restrictions on block size. Where is the primary processing/storage bottleneck? Is it in the temporary size of the mempool, (pre processing), or the permanent size of the blockchain? (post processing)
Storage (a hierarchy, in general), CPU power, and bandwidth are all potential bottlenecks and the future critical factor will depend in on the path of technological evolution which is difficult to predict. Most expect bandwidth, I believe.
Great timing from mike. Pretty much provides the answers I was looking for. Namely a fee market can and might develop around the mempool storage.