The marriage to Drogo was an arranged marriage, to help Viserys get the crown.

There’s a difference between who traditionally were her enemies and Ramsay’s enemies… And it’s medieval times. Again, she really only had it out for oppressors. She went through many areas w/o slaughtering everyone.

The whole mad queen, which might be foreshadowed in the books, was not in the show. The Mad King, the thing everyone pointed too, was caused by Bran. The “Mad King” was just fine. Just like Hodor was just fine until Bran came along. But because he never is like “oh hey guys, yeah, turns out the mad king saying “burn them all” was actually my fault” so the myth/legend around it always going to happen due to “reason”, at least in the show, falls apart. From my understanding, the books do foreshadow more of Daenerys’s madness and its possible edits from D&D end up casting her in a very different light. Which just echo’s how shit D&D were/are.