Two in character moments for Twilight mistaken for ooc

I am going to address these outside of chronological order.
1st, in Twilight's kingdom, Twilight says that she's not feeling like she's pulling her weight as a princess. I heard from one review that she hadn't wanted to be a princess before. That statement was probably influenced by Equestria Girls, in which Twilight complains about the future role of princess. One could take that statement in three ways.
First one could say that it is not TRULY canonical. If nothing that happened in the movie effects the characters later in the show (as stated by MM), is that not the definition of non-canonical? I agree: that seems like a cop-out answer to me also. The second cop-out answer is that Twilight wasn't in character (as may be shown later) in EG. That would mean that the conflicting statements are an in cannon conflict and you get to pick which one you like (yay). Finally, one could interpret Twilight as saying; I don't want a kingdom in some far off corner of Equestria, or to have to spend a billion hours chatting with dull dignitaries like I did in the gala. As you may guess, this is my preferred interpretation of her statements, but I feel that her complaint was poorly written.
But, where can we see that Twilight wants to be helpful as a princess instead of just plain old not wanting to be a princess at all? Well, let's look at the general Twilight attitude towards being helpful. Winter Wrap Up is all about her wanting to be helpful. And once she finds that role she looks constantly for ways to be helpful throughout the show without needing conflict. In fact, she's a natural born leader by the time she takes total charge in It's About Time. One can explain the whole of the first episode about her trying to be helpful. First she finds a reference and wants to help without being asked for it, or even when being discouraged by Celestia. Then she feels like she has to balance the important conflicting needs of the party vs. Nightmare Moon's return.
Now that was all pre-princess. But after she bacame a princess, in Trade Ya, Twilight seems to be bemoaning that she doesn't really have a significant role, rather than that she has a role at all. When Rainbow Dash asks for a hearing, Twilight takes it on without blinking -- not something a princess hater would do. The complaints Twilight has in the show about the Princess issue is that people are looking at the celebrity, not the position/person. And that is shallow and annoying to Twilight.

Now that the easy one is out of the way, I have heard the harder sell from TONS of locations. In Look Before you Sleep, Twilight is seen to have said that she ALWAYS wanted a sleeping party.
Cue the record scratch. Doesn't the fact that she wasn't into friends before she met the rest of the Mane 6 come in EVERY OPENING SEQUENCE? And, just in case you thought there was a reboot of sorts: her lack of desire for friends comes back in the song My Big Brother Best Friends Forever (that title needs shortening).
Wow, I have my work cut out for me proving that it was in character, don't I?
I think the answer is simple. Humans can be described to think mathematically. [Hah, I've tricked you into a science discussion!] So Twilight feels "I feel like I've known my friends forever." and "Forever and always are the same thing." When coming home from a busy day freeing Luna from her dark magical prison and all the ponies try to go to bed, I bet many of them couldn't go to sleep. I imagine Twilight was one of those ponies who was too excited to sleep. She was probably so excited that she felt she had to do something to remember all the things she wanted to do with her friends, like write a list. Waaay up on that list (first 15 out of 100 or so I'd guess) was probably, "have sleepover."
So now we have the mathematical thinking. "Ever since I knew you were my friends I've wanted a sleepover."
Ever since I knew you were my friends=I feel like I've known my friends forever. Therefore her mind's new statement is "I've wanted a sleepover since forever." I bet you know where I'm going, but I'm saying it anyway! "I've wanted a sleepover since forever." is the same thing as saying, "I've always wanted to have a sleepover." And without thinking her emotions twist up in her words and she temporarily forgets that she hadn't literally wanted to have a sleepover since the dawn of time. And this is what is so sweet about her statement: in some ways she has wanted to have a sleepover since the dawn of time; for her, the new dawn of time starts with finding her friends.

Totally canonical, totally in character, and totally the way people (and ponies) work.