What do you mean worthy of domain? If you want a domain, just get it..
But anyways, I love Inuyasha. And yes I think your site is "worthy" of a domain.. I like the.. pixellish parts of it. Although I don't like that navigation (at the top) pixel font. Also, you should've saved your banner at the top as a .jpg, since it has gradients.. but I guess that doesn't really have to do with much.
Hmm.. also, the tagboard I think shouldn't be in the enter page.. Are people going to browse your site, decide what they think of it, only to click the back button a couple times to get back to the enter page where the tagboard is? Consider having a guestbook and a guestbook page. And the enter page does seem kind of plain.. the gray backgrounds from the enter page and the indexx page aren't the same color.
The layouts that you make are pretty nice.. I love anime skins!
I've considered making a graphics/designs site for some time.. but I never learned how to code the php. Mainly the "previous | page 1 | 2 | 3 | next" thing.. God, I've always wanted to do that type of navigation. Mind helping me?
Well anyways. How long have you had your subdomain? Consider sticking with your subdomain unless your host wants you to move out or if you get LOTS and lots of hits. If you do decide to get a domain.. choose your domain name wisely, and perhaps create a poll that visitors can vote for the best domain name when you guys narrow them down. Er yeah.. good luck haha.