I do not know how far your physics relates to engineering applications, but I know for a fact that ASIC development will be a big thing in the Bitcoin space for a long time to come. It has to guarantee the steady price increase over the next 100-127 years of transaction verification and coin generation. Making these chips smaller and more energy efficient might be your best out.
Interesting that you mention this. While I am not training to become an engineer, I am moving into the field of nanophysics. I should read up on modern mining techniques.
why does the predicted mass of the quantum vacuum have little effect on the expansion of the universe?
Your question boils down to: why are our theories of gravity and particles not compatible? No one knows, and I certainly won't be the first to know. It isn't for a lack of trying though, as amazing hypotheses such as string theory, quantum loop gravity and what not, have essentially been developed to answer this question. None of them can be considered as true physical theories as of yet, though, as they are not falsifiable at the moment.
I am not a credible source on these issues, but I think that we will need new methods to reason about reality if we want to answer questions of this kind. There have been interesting developments in this area. As an example, I have recently found out about categorical quantum mechanics (you can find enough on google and arxiv.org if you dare [arXiv:quant-ph/0510032, arXiv:1009.3786]), which suggests a novel method to think about "state" and "change" and has the ambition to unify many scientific disciplines. My gut insinct (which is worth less than an educated guess) is that it is is proposals of this kind -- but not necessarily CQM -- that will really expand our understanding of the universe.