No, my approach does not require much extra computation.
Could you please point me to some literature on the well-known trade-off? I've read some things about that, but they seemed unpractical. I'd like to know if we're talking about the same thing.
By its very definition activated "Economic clustering" can't open new attack vectors in technical domain. Socioengineering attacks - yes, political attacks - maybe, but technical ones - unbelievable.
Is there a clear definition of how will "Economic clustering" be implemented? if you have a new consensus algorithm, there will be new strengths and new flaws. I'd rather not go into deeper discussion of something that is still not defined.
All this stuff is not systematized and I, unfortunatelly, don't have links ready.