You want bloggers to create content for your blog,or you want them to promote and drive traffic via social media posts.Those are two completely different tasks,and the second one can be done by people,who are not bloggers.Do you want volunteers,or you want to hire some freelancers?
Do you want search enigne optimization for your blog?
I`m sorry that I`m asking so many questions,but your post looks little bit unclear.
thank you very much for your precise question gives me something to think about
i need all 3 of those, for the project.