Good job on the site, in terms of the "art" page just keep in mind it will be a bit expensive to do so many colors in the first t-shirt design...however the second t-shirt design I think is great- the one with the huge big covered in blood coming around it. My only suggestion would be to bring the IMPACT down a bit, like it is in the VERY bottom...in the above picture it is far too bold...in fact it is in a different typeface. Instead keep it the same type face as below (some sort of proper or old english font) and just keep impact bold. Otherwise it really doesn't work at all with that old english right next to an art deco/ bauhaus font.
Your layout for the t-shirt is fantastic, really fine.
your digital art is fun as well- the photoshoped one is fine...not sure where you are going with but it works well in terms of graphic interest. The illustrator picture (i'm assuming) doesn't work that well. I can see what you are trying to do with the right side of the picture but you don't pull it together. Bring in some ideas from your t-shirts into there- i see you've already tried to put in the whole blood splotting effect and tried to keep the composition with the ubrella but it doesn't work I'm afraid.
Just trying to give positive feedback to a young designer- for your age you should really keep going at it..I'm 23 years old and recently graduated with a graphic design degree and a minor in art history, so I'm not trying to blow steam up your arse by any means. Just trying to help out- its my job and my life from now on.