‘…one real warning sign here: heavy, heavy shades of Daddy’s “burn them all” issue when she decides to tie Mirri Maz Duur to Drogo’s funeral pyre.’
Not really. As you say, it’s kinda surprising that the Dothraki who do stay with her have decided to stay with her, what with how her prospects look at that stage, therefore burning a witch is not only a killer political move from the perspective that she did horrible shit to their Khal, but also because the Dothraki are deeply suspicious of magic to begin with, a suspicion that she was wrong to ignore. It’s not just an act of revenge, it’s acknowledging her mistake, reaffirming her commitment to Dothraki beliefs, and showing power in one of the few ways that she can to her Khalasar at that point: showing that she’s not to be crossed. Besides, it’d be incredibly weird if a ruler in this world didn’t give an horrendous death to a member of the lower classes who’d openly admitted to deliberately doing something genuinely awful to her own partner/the ruler of their people.
Sometimes what needs to be done coincides with what you want to see done. Her father only thought of what he wanted to see done in his last hours.