I'm not sure if bitcoins deflationary nature would add to the parasitic consequences of financial speculation in drawing purchasing resources from the real economy,
Speculation only has parasitic consequences when 1) it is subsidized, or 2) externalities are not accounted for. Although Bitcoin subsidizes miners, it will probably not end up being a large subsidy and can be dismissed. Since Bitcoin is not a government, externalities are the real issue. And I'm not talking about externalities caused by speculation. I'm talking about real physical externalities that are not even widely recognized as such.
And even if it did perhaps the effect would be offset by the non-debt basis of bitcoin creation
This is the key. With non-debt-based currency, the supply doesn't need to fluctuate because the contrived concept of "demand" for money loses all meaning. Demand for money is infinite.
But people have got to get money for new enterprises somehow, from where then if not by paying a bank to create it?
From savers? Investors? People who receive dividends in return? Paying a bank to raid its depositors is not a viable method of raising capital in the long term.