These are my opinions on the matter, so do take them with a grain of salt, there's probably no scientific papers backing them up anywhere.
How does one go up to a stranger at a bar? How to even tell which stranger to engage in conversation?
There's really no way to know who'd be the right person to approach, other than your own gut. Does the person you're looking at make you feel interested in them? Do they look like someone you'd want to talk to? That's your answer. The fear of rejection or how you present yourself often blocks people from taking the first step or pushes them to be too forward, but important is to just open your mouth. The ice breaker can be something as simple as: "Hi, you look interesting, what are you up to?"
People often underestimate how they look or sound like, forgetting that the decision whether or not you're interesting isn't up to you in the end. It's up to the person you approach. If the person doesn't find you interesting or want to interact with you, there's very little you can do to change that, so roll the dice and say at least something. Rejection hurts, but hey, you took the swing. That's more than the other half that just sat there, doing nothing.
One of my problems is that I mostly need to interact with someone before I feel any sort of connection to them.
But if I start to interact with someone, and I lose interest, this could hurt them. I'd like to avoid doing that.
It's completely normal to let things develop on their own and develop interest over time. You might feel like it's a problem, but it's not. There's absolutely nothing wrong with that. People tick in different ways. Others can forge a forever relationship on the first meeting, others won't even call someone a friend after knowing them for years. With how rapidly everything progresses around us and the news feeds puking out rapid pace romances, social media showing our friends and families going from first date to wedding in a span of half a year, it can make anyone feel like they're falling behind. Or that things need to happen instantly. That you'd need to know on the first minute of the first meeting that this is it. You don't. The race is just an illusion.
As for the fear of hurting others... It's difficult to test the waters or interact with anyone without ever hurting anyone. Or have any kind of relationship was it romance, familial, or friendship. It can't really be avoided, but it can be mitigated. You can do things during the process to make things easier and to ensure things end up peacefully. Be honest. Talk a lot. Communicate your thoughts and emotions. A lot of heartache in romances comes from not understanding why things ended up the way they did. Making sure you and your partner or potential partner can communicate can cut all that in half or more.
I've become privy to the romantic history of others over my lifetime. For what it's worth, most people are actually quite lonely. It is the reason they put up with horrible relationships: Because its better than being alone.
Must romance always follow a fairy book story structure?
Must men always be predatory in dating?
There's as many ways to love and be in a relationship as there are people on Earth - everyone's story and situation is unique in a way, because we all want and need different things to feel happy and safe. We get fed a lot of lies and stereotypes of what love and happiness should be. One of the biggest lies we all get fed is that love and relationships are the be all, end all key to being happy. It's not. They can enhance your life and make it richer, but unless you really want it and feel the need for it, you don't need to pursue it at all. The mental picture that a person who is alone is somehow less than a person in a relationship drives a lot of us make bad decisions and hang onto things we really shouldn't hang onto at all.
It's easier to see a bad situation from the outside than from the inside. Many people in abusive relationships won't necessarily notice that they're in an abusive situation, 'cause that's their normal. That's the every day life they've gotten used to. Julia Lepetit's Frog comic is a good window into how things can be. A lot of times people snap out of it, sitting there thinking "How did I end up in this situation?". It's like growing a plant or a puppy. You don't even realize how things change, cause the change is gradual. The puppy that fit onto the palm of your hand is big enough to topple you over, and you don't notice 'cause you lived with the puppy every day.
Another lie is that love is something magical and will happen automatically. Bells will tow, trumpets sound, and you always have perfect chemistry with them. You will just run into your promised one and everything will work out by just being around. Sure, it can in some ideal lucky strike, but maintaining a relationship in the long run needs effort. It requires learning to know a person, it requires being willing to share your own life and space with them, and accepting their life and space as well - finding a comfortable status quo that doesn't impede on either person's freedoms or safety. You'll need to learn to share your interests, and accept the bad with the good. A lot of people get blinded by creating an ideal of what they want from a perfect relationship and then accept nothing except that perfection. They want the "immediately perfect" version rather than the "Am I willing to put in effort to make this work" perfect. After all a forever lasting honeymoon phase of dates and cuddles sounds more tempting than an every day life of folding laundry and talking about grocery store coupons.
We also get spoon fed the ideal that you'll need to find the One and live with them to the grave. You really don't need to. There's nothing wrong with having multiple relationships. It's natural to fall in and out of love. Relationships will start, and like all things, they will at some point end. The end of a relationship is not a failure. It's just your life moving onto another phase. Just like you might've lost touch with a childhood friend, or maybe you had a close friend in high school that you promised to stay in touch with after they moved elsewhere but never did. Romance is no different.
The wisest thing I ever heard was that "Love is forever, the target just changes".
As long as you and the person you're with are happy, with neither party being suppressed, oppressed, abused, or taken advantage of, you do you. There's a lot of pressure to get married, have kids, buy a red house with a white fence and all that, but you don't need to pursue any of that as long as your current life makes you happy and fulfilled. Rather than the outside image, focus on what works inside. What works for you. It's your life and your love.
Is it possible to date in a way that strengthens all parties involved, even if no relationship is born?
To this last question, I suspect that for a person to show interest in another person, this can in fact strengthen the person being complemented.
To some degree, success comes from confidence. When a person feels they have value, they can accomplish more.
Maybe its best to remain the skirmisher. The person that I appear to be is much different than the person that I actually am.
Far better to encourage than concern.
You sort of answered yourself there. Perfect relationships don't really exist. They all have their knots and tough spots. But from every experience we learn something of ourselves and the world around us. Even if it leads to no romantic happy end, it was still worth it, since you and the other person walked out of it alive and with a new look on life. Even if the lesson was just "This person wasn't for me", then that was already extra value. Now you know something you didn't know before, so time well spent.
How can I interact with real people when I have problems interacting with the real world?
When I was younger, I had thought I was perhaps something different than human. A machine, a spirit, an alien, something else.
Age has eliminated those doubts. I am in fact quite human. I'm just slightly less than human, in most respects.
EDIT: Feeling better.
The way that I've been approaching most of this is just wrong.
What I should be doing is trying to get to know people better.
Nothing wrong with using your own means and channels you're familiar with to interact with people. World is wide and scary, there's a lot of people out there now. To better your chances though, it's good to occasionally push your own comfort zone. Put your toe out of the boundaries once in a while. Don't push yourself to oblivion or to anxious state, but once in a blue moon, try communicating in ways you usually wouldn't. It'll help you get more experience in it and also make things easier in long run.
Humans are both complex and really simple. The term covers a wide variety of things, yet it doesn't take much to stop being human. A 4% shift in your DNA can mean you're still human... or a chimp. It all depends on what scientific field you look at it from.
And it's not that you're doing things wrong, you're just approaching from a different angle and thus seeing only a part of the picture. Now you've taken steps to another direction, see more, and learnt a new way to approach. There's not really right or wrong in this field. If there was, we wouldn't have so many articles and guides to dating out there.