Well it isn't the ladies forum so here are some answers from the other side,
"1.) Do ladies really have orgasms? Or do we just say we do? Like, is that a real thing? Or would I even know if I had one?"
despite being average or less and having every defect possible (ask any of the gals on the forum) I have managed to join Mrs Nail in orgasm using pretty much every PIV technique we've tried. And even had some limited success with other methods. So either she is a world class faker who keeps coming back for more, or I'm just very lucky in only one very narrowly defined area.
"2.) How often do people do it? Like is 3 times a week enough? 5? 12?"
yes, yes , yes all of the above and more. Everything from ABC sex (Anniversaries, Birthdays, and Christmas) to the old joke about royalty "once a king, always a king, but once a knight . . . is Never enough."
"3.) Is anal supposed to be fun for the girl? I have a pretty high pain tolerance, and still always end up crying. How does everyone else get through it?"
This is the part that is hard for a male to answer, because prostate massage is a pretty good thing, yes orgasmically good. But I have it on good report from Ducky Doolittle that at least one woman likes it.
"4.) When youíre married, what are the rules for saying ďnoĒ to stuff? I feel like Iím a pretty good sport and always try, but sometimes I just need to sleep or have a hard time with the pain. But if I try to say ďnot tonight, pleaseĒ it just ends up happening anyway, but more rapey lol... is that pretty normal?"
Rapey is not normal. Rapey is not good. I get turned down too much, but even at that it is very hard for a good man to be upset Because his partner is tired. or in pain. The Rule is always NO means NO.
"5.) How long is it supposed to take? Average? Like 15? 30 minutes? Couple of hours?"
Yes all of those or any of those, depends a lot on what you want to do. 2 weeks ago we spent 2 hours at it from wake up massage thru foreplay to a good one for each of us. But usually we don't have the stamina for that kind of performance.
"6.) Is it normal, over time, to become less interested in sex in general? I have such a hard time getting in the mood anymore. It just feels like Iím always faking it so I donít get in trouble."
Normal is not a good word in this kind of conversation. But to answer your intent:
People who aren't getting "satisfactory" sex often get bored. If you are never getting there, why warm up the engine?
People who have been in a long relationship with a restrictive partner can get bored of the same ole' same ole'.
People who are emotionally detached get tired of sex pretty damned quickly.
Some people have been married 50 years and still look forward to the next encounter.
"7.) Does anyone actually enjoy oral? I cannot for the life of me figure out how the porn ladies look so okay with it. I mean, Iím not opposed to doing it since itís expected to be standard wife stuff these days, but I have kind of a hard time getting aroused by choking, crying, and being deprived of oxygen lol"
This is actually the question I answered for. Yes I do enjoy Giving Oral. I enjoy it a lot.
Now having said all of that, @Faithful Wife
has declared the truth of the matter. It is clear, even to an emotionally retarded man like me, that your marriage has been sexually abusive instead of a loving bonding. In your place I would divorce. You have had enough damage for me to suggest a sex therapist if I knew anything about it.