My honest first thoughts ( please dont take this in the wrong way ) Is it needs a more customised theme ( even if its a free one you find on sites like this ) just to give it some character , Also instead of spending loads of money on marketing go and pay a professional to create a header / logo . No point in marketing a site if your bounce rate is through the roof.
Secondly i know its hard to no stick adverts on a site but i would leave it ( yup take them down ) at least for 3 - 4 months, while the forum is new you will most likely get pennies for in the coming months and ads like that ( that blatant ) will turn potential members away.
Once you have a nice looking theme you can then use a proper ad management system and actually make the ads look like a part of the site.
EDIT : also that header is too big, in actual size and the size of the file , 300k + image will slow your load times, you can easily get that down alot
EDIT 2 : Ive taken the liberty of reducing the image size for you, its now down to 100k. ( it will be ok at least until you get the site designed