SD has always had transaction fees.
When Mike Hearn and others are cavalier about block chain bloat, it's because there are
existing solutions being worked on. The process started with the 'ultraprune' branch that became 0.8, and will continue to improve. If all of the proposed optimizations are implemented, bitcoin can and will scale to VISA-level transaction processing, while being runnable on a commodity PC. It doesn't make sense then to devote valuable conference time to rehashing issues where we already know the work we need to do.
I would like to be snarky and negative about your project, but as I scan through it, I cannot say that I feel it is completely without hope. As best I understand it at least. So, I hope for the best and will be watching it with interest. Possibly even contributing if I feel that it is going in a way which will benefit me.
That said, one of my biggest complaints has always been that 'VISA-level' is actually pretty lame. Some biz guy at the conference mentioned the number of cell phones vs. the number of bank accounts. Something like 5x10^9 vs. 1x10^9. (I only heard this from a friend as I was attending the tech related presentations.) We are talking about some big big numbers if the worlds population is to gradually adopt distributed crypto-currencies as a means of transacting in economies.
Stratum was supposed to be 'the future of Bitcoin' as I recall ~moonshadow describing it. I sense that he was not looking at the big picture. I sense also that targetting 'VISA-level' will also fall into the same sort of trap.
If any one 'distributed crypto-currency' does NOT get into a scenario where it works in conjunction with off-{chain/backing/whatever} systems, it will likely mean that it has failed, and this is definitely the case with Bitcoin IMO. The question then becomes what the solution looks like at that point. Is it simple and reliable? Or is it complex and filled with new and unproven conceptual underpinnings and methods?
It could be the case that in order to provide even a workable 'reserve' capability, Bitcoin
would need to be 'VISA-level'. That is the basis for my interest in your solution, and again, I wish you well.
BTW, I hope you are not going to make the same mistake as Bitcoin in taking a 'C client defines the system' approach (or PHP or GO or whatever your implementation choice happens to be...) If so (vs. a more formalized specification) than it will count as a big strike against my hope for a solution which has long-term hope of success.