The rot currently prevalent in fandom culture insists that characters can only be what they were intended to be by the creators and anyone who says or thinks differently are clearly the devil and should be burned on a stake.
Excuse my French but that's bullshit.
Let's do a little exercise. Go get a book. Your favorite book. One you've read a billion times. Choose an expository passage. A small paragraph that describes some scenery would be a great choice. Now go get a friend. Or a family member, don't care, go fetch a human. Now both of you read that passage. Read it twice. Read it a third time. Do you have an image forming in your head? Great. Grab a piece of paper and have both of you go to separate sides of the room and sketch out the described scenery. Don't discuss it and don't peek. Don't be perfect. Use ten lines, a box, and four triangles, I don't care. I can't draw a stick figure either; stop complaining and just do it. Once you're both finished bring your pictures together and look at them side by side. They're exactly the same right?
Do you know why? It's because no matter how wonderful an author is. No matter how detailed a description I give you, everyone's brains are different.
Your mind has developed to be what it is based on your experiences; your joys, your trauma, your wins, and your losses shape who you are. You are different than me and so you are going to look at the world in a different way than I do. This directly affects how you perceive the world and in this case other people, including fake people... You know, characters.
I think the precipice you're standing on and rightfully scared of, is the one that everyone falls off of eventually. It's the "I know him better than you do" argument.
They don't know the character better than you do because they do not know that character as he is to you. They don't know what makes him so special to you because they have not lived your life. They have been infected by the rot of fandom know-it-alls. Trust me, I've fallen off that cliff. Still clawing my way up actually.
Oftentimes people like that (me!) see a lot of ourselves within the character. Or perhaps the character was a comfort during a difficult time of life. Or maybe they just really really like them. The character feels like a friend or a family member. And so hearing "wrong" things about how they're perceived by others can feel like a personal attack. Unfortunately most people lash out. That, I think is what you're scared of. And it's a valid fear. But also very very stupid.
So shake it off. Individual perception of a character's personality is unavoidable and should be celebrated. Get out there and write your character analysis. Go draw your blorbo as taller than what general fannon thinks. Write a fanfic that gives the character a pair of wings.
It's fake. You can't get fake wrong. Have fun and treat that block button like it's your significant other and your fifty year anniversary is coming.
