I ain't got time for a full reply right now, but it's replies like this that make me think you aren't reading my actual words.
This isn't my claim, at all, and it's never been. I'm not claiming the character is authentic. I didn't know what an "authentic" DL character was like, so I read some sources, and the character seemed to be authentic based on those sources. You don't agree, based on other sources.
My actual problem is that disagreement, and the fact that lore changes caused that disagreement. That disagreement is what hampers my fun-times and what I want to avoid going forward. That disagreement is the entire problem.
The cause of that disagreement, as far as I can tell, is different lore. If the lore was always the same, we wouldn't be in this situation (since I wouldn't be playing a gnome wild mage) and I'd be having more fun.
But, that disagreement is completely unavoidable. Not in any setting as large as this that spans that much time of the game's history.
If your goal is to create an authentic Dragonlance character and you only read a tiny sliver of the lore of the setting, why would you be surprised that there might be some disagreement? I'm kinda stuck on your stated goals vs the effort you made towards those goals. When we played a Dark Sun campaign, I did exactly the same thing you did - hit up Wikipedia and a couple of other websites and created a character that I thought was fitting for the setting. At the very least, it wasn't going to stand out as not fitting at all. After all, I didn't know much of anything about Dark Sun, so, if I want to play a Dark Sun game, I wanted to at least not be the odd guy out creating something that was way out in left field.
Now, would I say that my character was authentically Dark Sun? No. Not really. As play progressed, I realized that the Defiling thing was a much bigger deal and the character I made probably was bending canon pretty heavily. Thing is, the campaign simply adapted and we moved on. It wasn't that big of a deal.
But, at no point would I try to claim that my warlock was an authentic character. I borrowed from what I read, made it fit in with the campaign and moved on. But, again, my goals are not the same. I wasn't trying to make an authentic character. I was just trying not to make an oddball character in a very unfamiliar setting.
By "authentic" I'm taking you to mean that anyone looking at this character would immediately connect that character to a specific setting. Is that correct? Am I interpreting you correctly? Which, to me, means you have to dig a bit deeper than a couple of wikipedia pages and then expect that the setting canon has remained static for the past forty years. That's pretty unrealistic isn't it?
I'm looking at making a priest of Kossuth for a Forgotten Realms campaign. Now, this will be the third incarnation of this character who originally saw daylight in 2e using Faiths and Avatars. With the recent Forge Domain thing in the Unearthed Arcana series, I can get very close to my original character, but, it's still pretty different. After all, the 2e version could summon a fire elemental. The 3e version could do the same. 5e can't. Now, I could bitch and piss and moan that canon has changed and the game sucks because I can't do what I did before. I could do that. But, I'd rather shrug, move on and realize that my 5e version of this character is not going to be exactly the same as what I played 25 years ago or 15 years ago. I mean heck, Kossuth isn't even a god anymore. He's a primordial. I don't even know what that is.

So, I'll do a bit of digging and find out and then incorporate that into my new iteration of the character.
To me, it's more like how the Bond movies work. Every version of Bond shares some similarities, but, they are all different. Roger Moore's Bond and Timothy Dalton's Bond and Daniel Craig's Bond are all different. And that's a GOOD thing. What's an "authentic" Bond? I don't know. It's like what's an "authentic" Batman. Again, I don't even think that's a very good question. If I want to play a Bond character or a Batman character, I'm going to draw on the existing lore and then make it my own. It probably won't be the same as anyone else's Batman or Bond. It will be MY interpretation of that character. And the only real criteria for judging my performance is "do people like it?"