@brookr I think the most glaring problems are the layouts not covering the window on several screens. That's where I would start.
On the landing page fixing the secondary image alignments and either reintroducing some text, or removing that explanatory section entirely would improve the appearance. The white button text is difficult to read when it creeps up into the light portion of the image. Fixing the size of the about match button would be good, too.
The account creation pages look pretty good. The word, "submit" needs to be re-centered vertically in it's button.
When viewing your profile the "other technologies" label should align-right in accordance with the other three fields, and the link to gravatar should flow under the placeholder (and shouldn't appear if you have one).