Whoa, holy crap! Duuuude! This sounds incredible, absolutely professional! I mean, I like samples and all, but sometimes it's like a smack of deliciousness to hear a real instrument played with such skill. I really like the extra stylistic bits you added. You have a very good balance between your personal stylings and faithfulness to the original. The recording quality sounds nearly impeccable to my ears. I wouldn't expect to hear anything better from Square themselves. In fact I have some official Square arrangements on CD that aren't as good as this! I bet Uematsu would be proud. You should submit this to Overclocked Remixes and show 'em how it's done! Please, make lots more of these!
Most of them are mediocre, but there are a few talented musicians on there. Jeremy Soule actually has a piece there--search for his name on the site. Be careful; this site can keep you busy for hours if you're not paying attention to the clock.