As for the F-35 capability downgrades... What specifically are you referring to? The F-35's currently planned for RAAF service might, or perhaps might not, be as capable as those intended for USAF service. We do not know, such information, if it is even available, is not in the public domain. What would be better questions (in terms of aircraft performance) is whether or not the F-35A's planned for RAAF service will have the capabilities that the RAAF & ADF want and need? On a related track, what alternatives are there if one were to want something with the capabilities intended for the F-35?
Even if the LO features of the non-US F-35's are not to the same level as US LO features, it should still be something like an order of magnitude greater than the RCS reductions available in the SHornet, Typhoon, Rafale, etc. Now if the intent was to deliver a non-LO F-35, at the prices a LO F-35 would cost, then there would certainly be reason for complaint. Otherwise, the concern for the F-35 capabilities does not seem sensible to me.
-Cheers