Anal sex in a marriage

I am having issues. I am not arguing if it's allowed or not, it is just something that I need to clear up. 1. I keep reading that butt sex is haram because the word tilth is used in the Quran when saying go on to your wives the way you want to. But the same ayath is to justify oral sex, even though it doesn't get you pregnant. And does that mean contraception is not allowed? 2. They say it is not clean, but that's just a matter of opinion, and everyone showers daily, washes them selves, and keeps it clean. It is safe to assume that people are more hygienic now than ever before. 3. It is haram because it may harm her. With lube it doesn't hurt at all, and no medical reason for it to be harmful. It only hurts without proper warm up, and we are commanded to have foreplay so it shouldn't be an issue at all. 4. Also the hadeeth that forbid it, I read all over that they are weak, and shouldn't be taken into account because they contradict what the Quran says, go onto your wives how ever you want. (Allah swa is not shy to say the truth, don't have butt sex with your wives. And Allah swa will not look at him on the day of judgement who has butt sex with his wife.) I don't want to withhold something from my marriage because of opinions.