Good job Kacie
I like the way you are working with the faces of the characters. Chomper really looks very distressed at the idea of his parents' intention to go to the Great Valley. Speaking of idea, I like the idea of showing some family intern conflict about Chomper's befriending leafeaters. While we have very often discussed the problems Littlefoot and the others might have to explain their friendship with a predator to their folks we never paid much attention to the reaction of Chomper's folks to his befriending leafeaters.
This may be because we already saw some reaction in LBT 5, a reaction however that was very much under the impression of Littlefoot saving Chomper under the eyes of his parents. While Chomper's parents would not see the leafeaters as a thread to Chomper's safety (as which Chomper might perhaps be regarded by the folks of Littlefoot and the others), they might well see them as a thread to Chomper's sharptooth identity (translated as becoming "weak" and "hesitant" into the jargon of the sharpteeth). LBT 5 does show that there is some concern about this (in the sharpteeth subtitle during the song "Friends for Dinner"). You are making the whole conflict more interesting by not just making it Chomper vs. his parents but also making one of Chomper's parents more tolerant than the other.
Anyway, back to the comic:
Well, the black lines of the color borders shouldn't be so broad. They kind of resemble the color borders of an image from a coloring book (no offense). If at all possible, you should use a thinner art tool for the black lines.
I can't quite agree on that one. As far as I'm concerned the lines are quite thin (not too thin) already. Perhaps one might even make those lines which are very close to the eye of the viewer compared to other lines in the picture (e.g. the lines of the parent's leg in the second panel of the first page) a bit broader (but this is just a suggestion of which I don't really know if it would be an improvement).
I know nothing about how to create shadows with photoshop, but if it doesn't take too much trouble I think it would be an improvement. Even if the character's themselves would not be shadowed I guess it would look better if we saw their shadows on the ground.
Speaking of the ground, you claim to be horrible at backgrounds. Having seen your art at deviantart I must disagree with you on that one. The backgrounds in the pictures in which you used a background are quite good. I assume the sharpteeth in the comic are supposed to be in a very arid country. I think it could be made much more interesting if you scattered a few rocks and boulders, or possibly some skeleton or whatever else one might expect to find in such a wasteland. It would probably be some work, but it would also be some improvement.
One thing that really strikes me is the way you used colored airbrush lines to ascribe the text-bubbles to the characters. I know hardly anything about photoshop so far and it is probably tricky to create a text-bubble with a sharp white "pointer" as we know it from most comics. Still I think it would be a lot better if it was done that way, or at least if the colors of the airbrush lines would be identical (preferably white) rather than one for each characters.
There is one thing I noticed about the talk of the Sharpteeth. They mention the "Mysterious Beyond". I wonder if anyone but the residents of the Great Valley would even use that term to refer to the lands outside the Great Valley. It is the land they have been living on all the time. I doubt they would use that term.
In general I suppose Sharpteeth may have some terms the leafeaters wouldn't know about (but this is a topic for an own thread).
I'm looking forward to see the story continue Kacie
