"For example: structural risks (operational, concentration, leverage, liquidity, transparency); style/strategy risks (event, performance volatility); and systematic risks (commodity market sensitivity, bond market sensitivity, equity market sensitivity)."

I agree that risk is more than SD. But your structural risks can be minimised almost without thinking by a sensible portfolio-construction methodology (liquidity requirements, concentration limits, no leverage, etc.). Systematic risks can be summarised by the standard deviation of portfolios. I have done some work on the relationships between SD, VaR, maximum drawdown and other measures of risk (but not "permanent capital loss"; the risk of "permanent capital loss" is minimal in a diversified portfolio, unless the Martians invade). Basically, all these risks are highly correlated in back-tests of randomly-generated portfolio allocations. So, a lot of the time, SD is a good proxy for risk.