I looked at it all and I think you are really good! The things I would keep in mind is diversity - your portfolio should not be more than about 20 pages and those should together show off the total variety of your skill set. Drawings with some in progress stuff would be a great addition - art schools looooove to see your work in progress : )
I LOVE the landscape under "studies" it is so loose and wonderful in addition to showing me that you can do more than 'just' cartoony (not that cartoony is bad or anything ;).
I agree thst you should work on texture too, but I dont think you are too far off- just start by leaving brushstrokes on your drawings and figure out how they impact the feeling of the pieces :)
A third thing I would keep in mind is movement. Try to animate something simple (like a walkcycle for a stickfigure), then pick a frame where your subject is off balance and render that out somewhat - in order to teach you to draw with movement in mind and to show that skill off in your portfolio :)
I hope this helpe, I know that feeling of really wanting it while everyone keeps telling you that you are just 1 in a million trying to make it into these schools, but trust me, a lot of those many many people trying to get in do not nearly have what it takes, you just gave to make sure that you do :) you working on your skills (which are already pretty good) every day will take you there for sure :)
When I applied for the school I attend, there were more than 3000 people applying, but in the end only about 220 were actually considered for the 110 spots :) so if you have the skills you are not in the big pool :)