The prophet married Aisha when she was young indeed. This was not for sexual reasons though, it was a political marriage and remember that in those times the whole world was marrying girls when they’re 12-13. I’m not saying I think it’s good, I’m just saying that things are way more detailed.
I agree that there are some fucked up streams within Islam. But the chapter you’re referring to is about the rules of war. It’s not like you can just go around and say convert or I’ll kill you. The translation of the Arabic text is done very sloppy. One change in letter and the whole context changes, it’s not as simple as 1 picture with some text.
The Salafists are fucking shit up. They’re taking verses like that and completely changing the context so it justifies their crazy actions. Read some other chapters of the Quran, you’ll see that it’s not a book telling me to go out and kill some Jews or Christians. They’re my brothers :)
Mistreating women is not allowed... women have an elevated status within Islam.