Nice voice acting :D

Why is this on Newgrounds when it's supposed to be a YOUTUBE channel trailer? I DONT GET IT

YouTube. Not here

Dude you've been around for a while now, you seemed like a hard working guy, I've seen your stuff and I was kinda expecting something better.

All you did was put 4 assets:
head
body
2 for her left arm, possibly the worst ones
and her mouth flaps

And move them wonkily, without really any rhime or reason. The assets are not as good as any of your recent art.
You actually know better. But I think you rushed it. There's a lot of needlessly pixelated stuff as well. Sit your ass down, it takes weeks for a reason.

Trina was good though.

Okay, the idea and personality for this was really good. The concept is solid, and there are styles (maybe shortcut-ish) of animation where the facial components don't exactly match the rest of the head in motion. So, I'd go with style difference rather than for better or worse. It's humor, so we (audience) get to live with it.
I did notice the mouth generally kept moving through the whole time. I'm not going after the fact it was just a smile opening and closing, when I animate people, I've done the same so not an issue. What I'm pointing out is that she never ceased, even for a pause. It's nit-picky, but it also displays a certain higher level of skill and effort to have her visually pause between sentences and some phrases (of course as applicable) so she seems visually more natural.
The thing to remember here is that this isn't just an intro'. It's a teaser/trailer which is exactly a sales pitch. You're selling yourself, your skills (animating, writing, voice, sense of humor, etc...) to me (John Q. Public). You're treading into a well populated and competitive forum when you take up animating, so just a little looking around other animation based YT channels will easily show what mediocre is already there. I really mean this to help you out, and YOU NEED TO STAND OUT.
On this, like many others, the whole pitch is "breaking the forth wall" where a character is speaking directly to the audience. Now, this is only a suggestion, but where you ended with the fade to black and credits/messages with "But I'll still tickle you!" you teased / threatened. It's a joke, but it's along similar lines done before.
What if instead of admitting "But I can't...." She just admitted, "But I'm a cartoon..." Looked a little shy (blush or even play with her fingers, etc... the anime-girl stereotypical) and then rushed right up to the screen like it's a window. "Oh why not!" (or even something similar) Just a little work to "sell" the imagery of her lips pressing on glass at my screen, and don't forget to leave the "SWAK" lip-stick print thing as she backs off (still blushing and smirking) and then fade to black. You could even leave the lips-print deal for a link while printing everything else around it or even "behind" it like it's still stuck to the screen / window. I know, it's kind of silly and a LOT of work. I believe in you. You've clearly got some skill as an animator, and I think you could toy around a bit and nail it. You could probably throw in lines that are better than my suggestion and really sell this channel.
Admittedly, I neither know you, nor particularly the vision you have for your channel. I do have a little experience selling. Anyways, this is also just a suggestion, and most of these were small things to point out, so you're still a solid four-star (out of five ain't bad) rating.
Remember to breathe, relax, and keep on keeping on.