Website Structure for maximum benefits in seo

Friends

Hope you know seomoz.org

their pattern will be seomoz is the main site!

their most traffic earning part is thier blog

here is their model
seomoz/community
seomoz/blog
seomoz/resources
seomoz/about
seomoz/plans

and so on

the most traffic is entered and most traffic is used on seomoz/blog
through that they developed the way to conversion pages(seomoz service)

i am growing my own blog
my structure is

<ww*w.mydomain.com> is a wordpress blog
un professional theme i am using thematic

also my service page will be mydomain.com/service

My questions?
1.Does my current website model position is right i mean
>>>>>unprofessional theme
>>>>>><w*ww.mydomain.com>blog then mydomain/service

2.do i need special web theme?

3.Shall i still use wordpress blog on root domain(which my most traffic will enter) instead they are entered directly they will enter thorough my blog

4.or shall i change the wordpress theme create a professional looking one
then adjust settings like this

<w*ww.mydomain.com>/about
<w*ww.mydomain.com>/support
<w*ww.mydomain.com>/service(target con page)
<w*ww.mydomain.com>/resources
<w*ww.mydomain.com>/blog(traffic ent page)

by this way my wordpress still installed on the home page and my structure will be changed(i mean i don't need to move wordpres blog all i need create a new theme with pro)

also i had doubt? does wordpress good for landing pages? does wordpress support high coverting proffessional pages?

thorough this i will create high con pages!!!!

share your opinions