Tl:Dr - poop & duplicity are the most insane. The least controversial work is the Jews and Their Lies. That actually seems to be the work that holds up the best under historical scrutiny. Almost everyone attacking Luther in modernity has that as the primary target. I am not concerned about that.
The letters where he suggested ploygamy is OK and lying about it is OK, are nearly Mormon in their expression. I can't find an online source for this.
My first disturbance with Luther are very old. Some of the quotes from his pamphlets which recommended the abject destruction of the peasants who revolted are disturbing. Maybe it was just peasant antifa and there was plenty to suggest that is the case. There are also claims that his language originally written was further inflamed by copyists.
It's more difficult to put together, but there are cases where he seems to speak out of both sides of his mouth, this is particularly true of theological issues. I have been looking for ways to create citations, but so far even the internet archive is missing the quotes I'm looking for.
Also, the strange recurring fixation on poop is bizarre, I haven't tried to examine enough period German to know if that was just cultural. But, that seems a bit disturbing to me. It reads like the schizos who I know.
Many sources are difficult to find online, and all of my books are still packed from moving last year. High quality translations are upwards of $250.
I grew up with a near cult reverence for Luther. Over time, I have looked at the central claims. He wasn't really that fussed about the indulgences, he was primarily fussed about the guy and the methods of approaching the sales. That was shocking to me, given how that was a headline of the explanation of his significance. Luther's translation of the Bible. Into German was like the 15th or 16th translation, not the first. This isn't insanity of Luther, only the the absurd claims of people promoting him.
There are precisely zero untainted sources on Luther. Again, the only work he did that seems to be controversial only for itself is the Jews work.
Lots of the modern attempts to revisit Luther are strictly by Jews and Zionists in general.
- I think he is highly unreliable and that is why people have lionized the idea without great clear attribution.
- the ideas which have been communicated to me far exceed the actual work.
- The Jews and Their Lies appear to be fairly historically upheld (it's a long time since I read it).
- the theological distinction from the Roman Church are strangely unreliable.
- his doctrinal works are throughly Roman in their framework and concept, he just took great issue with the authority of the church itself, but his approach was to keep the central ideas of papacy atomized down to the individual level.