This...this is just nonsense. And I really don't mean that in a harsh way, I promise. But see, let's go over your points and I'll see if I can come up with a counterargument. I actually really love Twilight, she's the one I can relate to the most, and actually I'm very, very fond of her. So not defending her would be unthinkable, at least in my eyes.
1. Magic is something not needed in friendship. 'Oh, I'll show you my magic! Then you'll be my friend!'
Magic, in this show, is almost always referred to as "the Magic of Friendship". And think about it, it kind of makes sense--the Mane Six are six of the most diverse ponies ever born, they share almost nothing in common, they all have different careers/hobbies/interests, and yet they're better friends anyone could ever imagine. It does kind of seem like magic, when you put it like that.
2. What the buck is her talent?
I suggest going back and watching Boast Busters again. There, it's specifically stated that Twilight's talent is magic, and not the kind in the "magic of Friendship" I was talking about a moment ago. I mean spellcasting kind of magic. Her ability to learn and control magic is her talent, and when you think about it, that's a pretty awesome talent. Plenty of ponies have their cutie marks in other things, and yet are very talented at magic, but with Twilight and magic, it just goes hand in hand. In many ways, she didn't have a choice but to become Princess Celestia's student, and later, a Princess. When you see all of the backstory that her cutie mark has, it's really astonishing.
3. She's the most talented with magic in Equestria? Celestia, Luna, Cadence, I am disappoint.
She's not more talented than the Princesses. Celestia did say upon reviewing the results of her Magic Academy test, that she has more "raw abilities" than she's ever seen. The Princesses' magic is much more refined, and look at what they control; sun, moon, and love. Those are probably the three most powerful things in Equestria! And they control them! No way is Twilight more talented than they are. She's still very young, and working on her abilities.
4. Clearly stated by the book, Fluttershy has actually had the most growth. Doesn't that mean FLUTTERSHY should've been a princess?
What...what book?
And yes, Fluttershy has had a lot of growth and I'm very proud of her. But if you offered her the chance to be a princess, she'd hide under a table. Her personality, her cute mark, and her backstory simply don't align for being a Princess. Twilight has been specially selected, trained personally by the Princess, technically sent to a faraway land to continue the research of the most powerful kind of magic in Equestria (the magic of Friendship), and has overcome dozens of obstacles.
Yes, Fluttershy has grown immensely. But she would never take the throne, and she lacks the leadership and ability to take charge. I would also suggest rewatching Princess Twilight Sparkle, the Season Four opener, where it baldly states that basically the only one with any ambition of becoming a princess would be Rarity. (And that looked likely only for the fame and attention. Silly dear.) And the only one equipped to become a princess is Twilight. Looking back, three seasons have led up to this point, and while I have some major hang-ups with the rushed way in which Twilight became a princess, I'm thoroughly enjoying the idea of her being royalty.
I'm also going to deal with the second half of your argument in two points:
She's never really 'saved' anypony alone. Fluttershy told off a dragon ALONE. Flutters massage-rocked a bear alone. She also took on a cockatrice alone. What exactly did Twilight do?
Firstly, the bear was obviously a friend. So that would be like massaging a friend's back. Not very intimidating. Still, Twilight has done plenty of things. How about safely harnessing an Ursa Minor? How about saving the Crystal Empire, but allowing Spike to take the credit because she couldn't get there in time? How about being the only member of the Mane Six who didn't succumb to Discord's powers until the very end, and also the first pony to recover herself? And don't forget all the occasions where she organized both Ponyville and the Mane Six, in situations like a disaster coming from the future, a dragon slumbering over Equestria, and the delay of spring in Winter Wrap Up. Her accomplishments are very long and varied, and all of them correlate to her being a princess.
If Twilight really was a princess, she'd need all 5 things her friends have. So, if she's got that, why do the Elements even exist, then? Hmmmm?
Again, I would really suggest watching Season 3, Episode 13, and Season, episode 1 and 2. That pretty much encapsulates that Twilight does have the Kindness, Loyalty, Generosity, Honesty, and Laughter to become a princess. But that isn't why the Elements of Harmony exist. While Twilight is, in many ways, a good blend of all six elements, the other five ponies have that element as the core, defining trait of their personality. Twilight doesn't have that. It's been stated very clearly that Twilight needs the Mane Six as much as the Mane Six need her.
Honestly, I wouldn't be writing all this if you had just stated good, solid reasons for dislike Twilight and Twilicorn. Plenty of people don't like Twilight, and almost the entire Brony fandom hates Twilicorn. But there are plenty of well-thought out arguments against Twilicorn, while your first post seems very incoherent. And also much more suited to, perhaps a blog post.