Constructive criticism: The first page looked like an opt-in or a launchrock page. I almost left because I didn't want to sign up for anything. Looks cool, though.
At least. For me, a picture background offset with a dark background and light text says "temporary landing page" - like your website hasn't been set up yet (see http://launchrock.com or http://grasswire.com to see what I mean).
I would definitely center the "get started" and move it up to just under "express yourself."
I would also change the messaging on the button so it's less ambiguous. Instead of "get started" say something like "start designing." I'm just not sure what "getting started" means. That should up your clickthrough rate and lower your bounce rate.
Definitely. Making a t-shirt seems to be the one action you want people to take from the landing page, so it should be represented as a big honking button saying "CLICK ME!" (More elegantly designed, of course.)