Snapedom

We all remember the great Snape debates before DH came out. About where his loyalties were as of the end of HBP, when they changed if ever, how many times they changed. I think we agree that DH settled this question (even if we don't know the exact time-point we know which events triggered the turning points in his path). Another question was how far he went as Death Eater. After DH the consensus in this forum seems to be that canon suggests either at that he did not go as far as killing, or that if he did he fully repented for such killings and healed his soul to the extent that is possible. It is clear from canon that whatever he was as a Death Eater, the man we see during Harry's Hogwarts years is a man with a strong conscience, with a clear view of right and wrong (despite having to act on the edge due to his role as a spy), who does not make light of having to commit harmful acts for a long-term beneficial goal.

But even without ever killing anyone directly, with his own hand/wand, there is much he could have done. The most obvious is the brewing of poisons and other harmful potions that were then administered to innocent victims by others. Then there is the invention of new harmful, potentially lethal spells, and teaching such spells to other DEs, thus resulting in injuries and deaths among their victims. I think the worst I have seen in fanfics is Mengele!Snape - Snape in his DE days using captives (mostly Muggles) to test properties of newly invented potions. Some scenarios get extremely gruesome, with a team of DEs at Snape's command cutting through a still living victim so that Snape could observe damage to internal organs as it took place.

So my question is, would knowing something like that change anything in your attitude to Severus Snape? Is his complete repentance enough for you as a reader to disregard anything, however cruel, he may have done in his dark period, or would the thought that this was a man who may have been capable of such horrors disturb you enough to feel you cannot forgive him completely? Do you think a man who had commited such actions is capable of abandoning them for good or would he always be at risk of backsliding?