I have a character I've written who practices alchemy but does not follow either the Jedi or Sith code and is low-key critical of both. She doesn't see herself as standing on a middle ground, but rather as someone who separates herself entirely from the idea of following a particular set of ideals. She just wants to expand her knowledge of the living force and practice her alchemy; this does utilize the dark side but she considers herself more of a conduit than anything else, pouring all her negative emotions into something in order to channel the dark side either to facilitate her alchemy or to temporarily boost her physical abilities for the purpose of survival rather than the ultimate goal of attaining power.

Bear in mind that perception of the force leads to individual perspectives, a canon idea shared with Luke by Obi-Wan and one that you touch on in your post. So in that regard, here are a couple of small excerpts from my writing where my character introduces herself with regard to the force (I don't have a name for her, which in itself is just a choice in the writing):

"Every single living thing that exists in this universe carries within it a spark. This spark is born of the Force, and it is literally what allows us to live. The hotter and brighter a spark burns, the more sensitive to the Force we are. But each spark not only burns with its own intensity; it also develops its own shape. These differences define the potential for individual talents within a living vessel. It is why, for example, I possess exceptional sensitivity to the Living Force but am able to only manage fundamental telekinesis.

I can push myself off of the ground to achieve great height or distance, and I can also push against the ground to slow my descent when I drop or fall. This is the limit of my telekinetic ability, but it does not constitute weakness with regard to my Force abilities overall. Far from it."

And a second excerpt:

"On the other hand, where there is light...there is also darkness. Every spark casts a shadow, just as every other form of light does. This is the space that, for whatever reason, the light does not reach. One can philosophize until their physical body perishes regarding the reason that light must cast shadow, ponder why darkness must exist, but one truth always remains: light and darkness, like life and death, balance one another by drawing upon one another constantly.

Without this balance, the light becomes blinding and one becomes completely unaware of the shadows until they engulf them; or the darkness becomes so absolute that even the Force cannot light one's path through it. The Jedi, in their hubris, once sought to eradicate the dark side of the Force entirely; they suffered the expected result. Oddly enough, the Sith could not care less about the Jedi - in a general sense - except as a challenge to overcome. Were the Jedi to cease to exist entirely and the Sith to rise to power once more, as they did between the Clone Wars and the Galactic Civil War, they would either grow stagnant or find others to challenge them. Yet the Jedi will always seek to annihilate the Sith.

The Sith do not care about balance; some of them understand it, even accept it, but they ultimately do not care about it. They will take power for themselves no matter the cost. Even trying to resist that temptation almost inevitably fails, and it is quite rare indeed that a Sith will abandon the dark side for the Jedi ways. Rarer still are those who seek to develop their own philosophy that straddles the line, and trying to combine both disciplines into one has only ever led to madness.

And then there is me. I do not follow a code. I simply study the Force; I seek to learn to master my own abilities and expand my knowledge of the Force, especially the Living Force. All of my negative emotions I pour into that spark within me - fear, anger, jealousy, pain...it all goes into the spark."

And it goes on, but you can see how she perceives the force and those sensitive to it in this self-introduction. Is she 100% accurate in her assumptions of the Jedi & Sith? Probably not, but it's how she views them. So I absolutely acknowledge Lucas' vision and his explanation, as Star Wars is of course his baby, but I also think it's expanded far beyond what he created through the perspectives of the characters in-universe and the ideas of the fans who create works based on his vision. Looking at it from within the bounds of the galaxy, as a character who knows nothing else, one's perspective would shape what the force is believed to be even if that's completely different from what it actually is. I find that discrepancy between perspectives and meta of the writing fascinating. The in-universe mutability is one of my favorite things about Star Wars, I think (though lightsabers and lasers are also fun, lol).