hashtorani,
As far as referring to MO/DL as kofrim/ovdei a”z, I agree with you that is wrong to call them that but did not notice him referring to them that way, only to the beliefs espoused.
HaKatan wrote this extrapolation of Rav Elchonon earlier in this thread:
So, according to Rav Elchonon, if you are a proud Zionist (which, according to their theology, includes “MO”) then that makes you a proud oveid A”Z.
While Rav Elchonon may have declared secular Zionism to be a form of A”Z, I highly doubt he pointed fingers at specific groups of Jews and declared them to be idol worshippers. Furthermore, it is clear from HaKatan’s analogy with the worshipers of the baal in the days of Eliyahu HaNavi that he believes the majority of Jews today are infected with this A”Z.
If this were truly how we hold, then since U.S. vaads likely don’t use Zionism as a litmus test to screen out mashgichim, one could not trust any U.S. hechsher. Since the vast majority of rabbonim in the U.S. don’t ask eidim at weddings if they are Zionists before accepting their testimony, then we cannot trust the majority of kesubos.
Somehow I doubt that HaKatan really holds that way, so it might be a good idea to be more cautious with the rhetoric.