"How do you find a religion that's right for you? One you're happy in? Every path I've gone to, I've come away from because it hasn't fulfilled me spiritually in the end. I've been on this spiritual search of mine for ages now, and it's just not going anywhere. I can't find one I 'agree' with about 75%, much less one I totally agree with."
I would say that part of the problem is your theory/understanding of religion. This is by no means a personal criticism, as how you phrase the question shows the standard theory of religion in the modern West. And, it is the theory presented in Religious studies courses. Yet, this very model sets one up for the lack of spiritual fulfillment you have found.
I've actually put together an entire course to help people consciously approach religion, due to the length I can only share some key points.
You can "hear" religious teachings as different voices: instructions to do certain things, instructions to don't do certain things, or instructions to transform, a fundamental act of becoming. The latter is what is often hardest to see. Sometimes is is easier to see it in a distant religious tradition. For example, many in the West can see this only when they look to the East, or modern peoples when they look at premodern or indigenous traditions. Yet it is a part of all major traditions. And it is the way in which there is a spiritual path within religious traditions.
The main thing to find in a spiritual path is a means of spiritual growth and personal transformation. It needs to include spiritual exercises, things that engage oneself in something other than default habitual existence. It needs to challenge you and engage you in an expansive way, not just take up your spare time with studying what other people have said about this or that. If the mythos, scriptures, stories, or symbols don't meet with some inner resonance or "make sense" in a deep way, it is probably not the right path for the long run. (It would require a great deal of preparation, and may end up being understood in terms of one's own cultural religion anyway. This is why the Dalai Lama says to follow your culture's religion).
If you find a path that has a practice, that engages you internally/spiritually, and challenges you to grow, then you need to spend time and work discerning if indeed this path and this particular instance of this path are for you. Most often people will misapply criticisms from their cradle creed, and this occurs long after any other aspect of that religious tradition has been left behind or rejected. So, try to be aware of such issues. If your earliest religion rejected this or that, you will probably reject any path you come across for the same reasons. It doesn't matter what they are: high church, low church, bible version, starting a circle in the West, crosses, crucifixes, Statues, pews, cushions, indoor, outdoors, paid clergy, any clergy, kneeling, silence, preaching, prayer books--you name it. I have seen people try to remake an entire religious tradition to avoid internalized cradle creed criticisms. So, this is a serious issue. If it something that you don't want to take on, then include them in your conscious criteria as comfort issues.
A genuine spiritual path will offer support, comfort, and some guidance, but won't pretend they can do it for you. The metaphor that I find fits the situation best is climbing a mountain. You have to do the climb, but you don't have to do it alone without training, equipment, or guides. Ultimately, you must rely on yourself in that way, but you don't have to go it alone.
Progress on a spiritual path requires commitment and hard work. Often people will feel a certain expansiveness or have a period of spiritual experiences when starting a path, then may leave when they hit the first dry spell. Such cycles are normal, and if you have made progress on a path, continuing makes sense.
The journey is the point, if you feel comfortable, complacent, safe, then it is time to change something in your practice or approach, which doesn't necessarily mean changing paths, but it may. Some religious organizations take people through a particular transformation experience into a state of complacency, which ultimately is not useful.
"It's not about how I view religion; I just don't want to go to a religion which I don't agree with the majority of, or one where I disagree with some parts, which in turn are extremely important. An example of this is not believing in . . . .
"If I can't agree with the main points, how can I feel spiritually fulfilled? I am fulfilled when there is harmony, and the paths I have taken in my time I have not agreed with certain key areas, so I've gone away from that path."
I will still suggest that what you mean by "religion" is a very limited modern Western view of religion. You stress certain beliefs for example. In my tradition, and some others, rigidly held beliefs are a hindrance. You can then say that these aren't "religion" because they don't fit the standard modern Western model, or you can begin to expand your understanding of religion to include them. (This is an example of accommodation, making the model fit the data, as opposed to assimilation, making the data fit the model.)
Other than what William James once called the "healthy minded" personality, I honestly can't think of any serious suggestion that having particular beliefs will lead to spiritual fulfillment, and I have read widely in the subject. Or, framed another way, if it were merely a matter of comfortable or compatible beliefs, then your own beliefs right now should serve as well as any other set. I'm not trying to be glib, just trying to help you see beyond the model of religion that has been given to you, which is a very difficult thing. Many people are much more willing to literally destroy the world than attempt such a task themselves.
You have stated certain criteria of things you want to avoid, yet rejection is really a shaky way to build a religious identity, let alone engage in a spiritual path. Forget the theology, the beliefs and practices, and other aspect of the model of religion, at least for a time. What myths or symbols have resonance for you? What spiritual practice do you find rewarding? If you don't know then explore some. Attend a few services, particularly if they are group spiritual practices rather than lectures, and see what happens inside of you. Try not to think about it all so much at first.
The spiritual life is first of all a life, an experienced livingness. The abstract takes us away from the experience. Once you find one point of connection of that inner life with an outer form, once you have found others like yourself, the rest will take care of itself. For a spiritual path is first and foremost a path of lived spirit, the path you feel more spiritually alive in following. The rest is there to be of service, or to weigh you down or hinder you. Set you feet on the path of life and the rest will follow.
Blessings on your journey.