Bilam's curses - the approach of R' Y. Bloch

On Shabbos I found that the Shiurei Da'as (in the essay "Nes v'Teva" I) touches on the question raised last week - if Bnei Yisrael were not deserving of punishment, then why stop Bilam from idle rambling? R' Bloch draws a comparison to the malach hamashchis of makas bechoros - why the need to paint the doorposts with blood if Hashem protects the innocent? The solution seems to be that these spiritual forces operate as part of the teva. Just as one would not say that germs do not affect tzadikim or tzadikim can be healed without antibiotics, so too with respect to spritiual forces, the curses of a Bila'am or a malach hamashchis have power that stems from the nature of the world as Hashem created it. Within that "natural" framework, there also exists spiritual tools to thwart that power or earn a level of immunity. R' Bloch defines one's "shiur komah" as the degree one is spiritually aware of these laws of nature that operate outside the threshold of our empirical awareness.