I think it evades an evident truth however that we are all interconnected. My individual actions affect the livelihood of others without choice. Not only is the action of imposing our beliefs controlling, it is also an action to protecting our immediate interests and we ALL do this.
True. But I think most people would agree, practically speaking, that there's a limit to how much control others should have over our behavior (or we should have over theirs), despite the fact that we are all connected. For instance, maybe the way Joe (random guy I just made up) treats his kids affects how his kids treat Shigeru's kids at school (another dude I made up). Nonetheless, I think virtually no one believes that Shigeru therefore has the right to go over to Joe's house whenever he wants to perform random inspections and tell Joe how he can and cannot interact with his own kids, what he can feed them, how much exercise they get, etc. Or say that I am a fruitarian and believe that it is wrong to kills plants for food, and it is deeply distressing to me to see my next door neighbor harvest his carrots. Again, virtually no one, however, really believes that he should have to stop growing carrots because it causes me emotional pain. On the other hand, if my next door neighbor were killing my pets to make sausage out of them, or Joe was encouraging his children to attack Shigeru's kids with baseball bats every day, most people would believe that the offended parties had a right to curtail that behavior. But then we're left with a morality that's determined by "what most people think," which as I said before, I don't really view as inherently more valid than "what one person thinks" (you're less likely to be held hostage to the whims of one nutball, but on the other hand, entire societies are perfectly capable of reaching moral consensus in favor of completely egregious things, so I don't view it as any guarantee of morality).
It is convenient if you can instead go by "what God thinks," if you have a sufficiently stable and homogenous and (some would say) superstitious society that most everyone who lives there can agree on what God thinks. The problem with this is that 1) a lot of people don't believe in God(s); 2) those that do believe often still don't agree on how He thinks they ought to behave; 3) those that do believe tend to think that believers in different Gods or even in the same God with a different twist are not only wrong, but possibly ought to die, and it often leads them to do things that would be considered morally wrong if it weren't for the fact that they were doing them in the name of God; 4) some of the things that people decide God does/doesn't want us to do are either outright trivial, have nothing to do with "morality" as most people would understand it, are actively wrong going by any other moral standard, or seem to be oppressive toward particular groups (gays, women, other ethnic/religious groups, etc.)
The only way people will willingly submit to a moral code that they dislike or disagree with or find incoherent is if they genuinely believe that God exists and that He made up these rules. Without belief in a superior being, I cannot see how an absolute moral code can exist. Things like government (bureaucrats & politicians) or elders or an elite of some sort can stand in as "superior beings" of a sort, but I don't think they actually are, and most people recognize this on some level, and so I don't see how moral absolutism can function in today's world, and especially not comparatively between cultures or even generations.
Before, I proposed "demonstrable harm" as a standard to apply in determining whether I ought to have the right to impose my beliefs on others and to what degree. That doesn't really solve the problem--as I said before, some harm can be demonstrated but is so trivial or so indirect that we don't think it gives someone a right to interfere. But I can't think of a better litmus test, really, certainly not an absolute one.
There are also practical limits--the quote you mentioned about controlling how people have sex is one example. It's often true that people's irresponsible behavior gets subsidized in a society in which risk is socialized to a degree (a "welfare state"). On the other hand, what are we going to do, have a penis inspector who goes around and makes sure everyone is suited up before they get it on? Medical costs are also spread out, to a degree, but is someone out there going to tally up the donuts I buy at every check out counter in town and attach trackers to my body in order to ensure I spend sufficient time each day exercising at a moderate pace because other people might end up contributing to my eventual treatment for diabetes? Should I have to undergo genetic testing, along with any potential partners, in order to determine that our future children are unlikely to possess any heritable disorders that might cost future taxpayers money? I am also frankly suspicious of the motives of most people who make these kinds of arguments--I think mostly they feel an impulse of disgust or judgment or superiority, and then rationalize it with such arguments. Of course not in all cases, but often.
For example, I don't think anyone here can truthfully say they don't impose their beliefs to others when they challenge people to recycle waste, conserve the forests, go vegan, build natural, etc....
Hmm, I think there is a big difference between a moral judgment being encoded in law and punishable thereby, versus it being enforced by widespread social shunning and discrimination (or even cold/hostile behavior on an individual basis), versus it just being something that you are simply asked to do/not to do. I don't think that asking someone to recycle is imposing my beliefs on them. If I get together with the whole town and refuse to speak to them until they start recycling, yeah, that would be a form of enforcement. If I fine them, throw them in jail, or summarily execute them, that's definitely imposing my beliefs on them! Human beings will always naturally try to get others to behave as we want them to behave, but we do have a choice about the means we use to do so.