Avi – all is indeed known, Hashem knows the future and sees it happening, but Hashem gives us free choice; that’s the old contradiction and dropping one part of it because it lets you feel secure with an Uzi won’t solve the problem. It remains that nothing can happen to you without it being from Hashem – that’s the chovos halevavos in shaar bitachon, the nefesh hachaim and virtuall every machshava sefer ever. We have a mesorah even that every minute thing that happens is hashgacha, even though there is seemingly a shitah that says that small things might not be – the seforim explain that rishon to mean that it’s relative…we don’t see the hashgocha in the small things, so le’umasaeynu it’s as if it isn’t there.
For a very good explanation of the ohr hachaim and this topic in gener, see rav chaim friedlander’s sifsei chaim; the ohr hachaim doesn’t mean that you xan6chNge6a gezera from shomayim…he means that with bechira, you can be meorer dinim on a person and they can be judged in shomayim more severely than not – it’s like when someone is in a tzara lr be’idna dirischa, things happen that otherwise wouldn’t, but “hakol tzafui veha’reshus nesunah” is axiomatic. When paroh said to Hashem “why are you blaming me? You decreed that bnei yisroel should suffer” Hashem answered “who asked you to be the shliach?”. Wicked people end up being the shluchim for bad things and good people the shluchim for good things.
Rabbi Soloveitchik fits into category B as mentioned above; those who believe Hashem caused the holocaust but eschew giving reasons. This opinion was very popular after the war, and still is among balebstishe people. It’s not treif, it’s just putting your head in the sand in my opinion. Also, many rabbis after the war did not want to offend survivors – this has a basis in chazal, as the gemara says it’s onaas devorim to tell someone that you’re suffering because of your sins. Rav avigdor miller, and the gedolei olam such as Rav Shach had no problem saying repeatedly that it was a punishment, but others did shy away from it, so that is worth mentioning.