I agree with everyone here. But I do have some separate thoughts.
Bulk redirects aren't negative if they are done correctly. For example, I just moved a website that had about 1000 discontinued products. As opposed to losing those valuable pages, we redirected them to the corresponding category pages or to the replacement products. The 600 or so links that had to be redirected to a category aren't going to hurt my site. It will help my customers who are looking for those products, however. A client would probably rather land on a page that says "this product is no longer available, here are the replacements" than a 404 error page.
In the case of a blog, it is a lot better to redirect each blog to its new home. For blogs that no longer exist, I would redirect them to the corresponding category. No one likes to hit a 404 page, and if there is a chance that someone could land on a page that no longer exists, it is better to have them get to somewhere on your site.
As far as your blog's home page, is that a separate category on your site or is your entire site a blog? If your page was just a landing page where your blogs were listed, then you should redirect to the corresponding page on the new site, like Jonathan suggested.