Sorry cobber, but the logo is offline in every browser for me, even Chrome. So maybe try shifting its position a bit ... though it's hard to get it right with the method you've used, as you never know how big a user's fonts are going to be.
The font looks the same to me in Firefox as other browsers. It's a bit small, and looks better at bigger sizes. You only have Open Sans listed as a font, though, which is a bit risky. Have some fallback fonts in case a user's computer doesn't have that font. Also, it might be worth sending the font with the site, using @font-face, as that font is available online. That way, you could perhaps use the actual bold font, rather than setting it to bold via CSS, which doesn't always look great.