Why style headline and button similarly?
I think it's safe to assume that forms have been around long enough to expect most conventions to be religiously respected. However, very often it happens that you go through a nerve racking sign up form. This is particularly disappointing considering forms are essentially everywhere on the digital world.
In this case, the Submit button is not a typical button; it rather is styled text. To make matters worse , the text has the same colour like the main instruction for the form, which makes it look like just another line of text. Certainly the Submit bold text makes it stand out, but making it an actual button, that actually affords clicking wouldn't hurt, would it?
Quick fix: Putting a rectangle around the Submit text actually turns into a button, thus affording clicking.
Now, the button can be placed on the left, aligned in the centre or on the right. My stance on this is to put it on the left when its a submit button- so as to indicate a vertical flow that ends here, and place it on the right when its part of a bigger flow, thus prompting the user to move on to the next chunk.